CALCIUM (Calcium, Ca) — chemical element II of group of a periodic system of D. I. Mendeleyev, belongs to alkaline earth metals; has high biological activity, is the main structural component of bones of a skeleton and teeth of animals and the person, and also important a component of system of a blood coagulation; salts K., arriving as a part of food and being acquired by an organism, significantly influence a metabolism, i.e. To. is an irreplaceable element in food of the person. Connections K. strengthen protective forces of an organism and increase its resistance to external adverse factors, including and to infections. Some salts K. are used as pharmaceuticals. Insufficiency or surplus To. in an organism can be the cause or the investigation of a row patol, states (see. Calcification , Kaltsifilaksiya , Osteomalacy , Rickets ).
Contents To. serves as auxiliary diagnostic test at some diseases in blood serum, urine and Calais.
Sequence number To. 20, atomic weight 40,08; natural To. consists of mix of six stable isotopes from which it is most widespread 40 Ca.
Metal To. is for the first time allocated in 1808 Mr. of Davy (N. of Davy) who called a new element calcium (Latin of calx lime). To. it is eurysynusic in the nature, its connections — limestone, marble, gypsum (see), lime (see) from an extreme antiquity were used as construction material. On prevalence in the nature To. takes the fifth place.
Density To. at t ° 20 ° it is equal to 1,54 g/cm 3 , heat conductivity at t ° 20 ° — 0,3 kal/sm-hails-sec., ud. heat capacity (0 — 100 °) — 0,149 kal/g-hail, ud. resistance at t ° 20 ° — 4,6*10 - 6 ohm-cm. In connections K. dvukhvalenten, it is chemically very active. At a usual temperature To. easily interacts with oxygen and moisture of air. During the heating on air or in the presence of oxygen forms an oxide — CaO. Interacting with a cold water, forms a hydroxide — Ca(OH) 2 . To. reacts with halogens - fluorine (in the cold), chlorine and bromine (at a temperature over 400 °), forming according to CaF 2 , CaCl 2 , CaBr 2 . During the heating without access of air with graphite, silicon and phosphorus K. forms according to CaC 2 , Ca 2 Si, CaSi and Cs 3 P 2 , and with metals (Al, Ag, Cu, Mg, Pb, Sn, etc.). To. gives intermetallic compounds.
To. it is capable to form strong connections with proteins, phospholipids, organic to-tami. Thanks to these properties K. not only carries out an important plastic role during the formation of fabric structures, but also influences many fiziol, and biochemical, the processes which are constantly proceeding in a human body and! animals, participating in regulyation of permeability of cellular membranes, in electrogenesis of nervous, muscular and ferruterous fabrics, in processes of synoptic transfer, the molecular mechanism of muscular contraction, in implementation of secretory and incretory processes by digestive and closed glands, and also controls a number of enzymatic processes.
Contents To. in an organism of the adult makes apprx. 20 g on 1 kg of body weight; at newborns — apprx. 9 g on 1 kg. Main part K. (99%) contains in bone and cartilaginous fabrics (see. Bone , Cartilaginous tissue ) and in teeth (see). In these fabrics K. the kaltsiyfosfata, connections with chlorine, organic to-tami, etc., other part — in cells of soft tissues and in extracellular liquid is found in the form of a carbonate. Concentration To. in a blood plasma of the person and the majority of mammals makes apprx. 10 mg of % (2,5 mm). To. plasmas it is presented by two fractions: diffusing (complexes K. with proteins) and not diffusing (ionized To. and complexes K. with to-tami). In a blood plasma To. it is connected with four fractions of phosphate — proteinaceous, lipidic, acidsoluble and organic. On a share To., forming complexes with proteins, one third of total quantity is necessary To. blood plasma (concentration of 0,82 mm). Albumine, beta globulins and cephalin have the greatest kaltsiysvyazyvayushchy ability. Complexes K. with proteins some kind of depots K serve in a blood plasma. in an organism. Concentration ionized To. in plasma makes 1,33 mm, and complexes K. with phosphates, carbonates, citrates and anions of others organic to - t — 0,3 mm.
1 g of protein of uniform elements of blood contains 2,5*10 - 4 asking To. Membranes of erythrocytes, an active metabolism have high kaltsiysvyazyvayushchy ability To. occurs in thrombocytes. To. is a necessary factor in the course of a blood coagulation: in absence To. there is no transformation of a prothrombin into thrombin, and the blood stabilized by addition of the connections connecting ions To. (e.g., oxalate or sodium citrate), is not curtailed (see. Coagulant system of blood ).
In cells the main part K. it is connected with proteins and phospholipids of cellular membranes and membranes of organellas. In kernels To. it is more, than in cytoplasm. Are richest To. kernels of cells of a liver, pancreatic and thymic glands. Ability to accumulate, and in case of need to release ions To. mitochondrions possess. Process of accumulation of ions To. it is accompanied by electron transfer and accumulation of inorganic phosphate. At the same time there is no oxidizing phosphorylation: energy of electron transfer can be used by a mitochondrion or for accumulation of ions To., or for synthesis of ATP, but not for both of these processes at the same time. Kaltsiyakkumuliruyushchy ability of mitochondrions gives them the chance to participate in processes biol, calcinations y decalcifying, and also in relaxation of muscles.
In the mechanism muscular contraction (see). To. the special role belongs. The greatest sokratitelny activity of a skeletal muscle is observed at concentration To. apprx. 10 - 7 — 10 - 6 M; at decrease in ion concentration To. to <10 - 7 The m muscle fiber loses ability to shortening and development of tension. It is known that reduction of muscle fiber results interaction of two main myoproteoses — a myosin y from actin. At rest this interaction is blocked as active centers on a molecule of actin are closed by a regulatory proteinaceous complex. As the factor allowing reduction serve ions To.: at increase in their concentration in a myoplasm there is an accession To. to regulatory protein therefore actin becomes capable to interact with a myosin. Connecting, these two proteins form actomyosin, and the muscle is reduced. In the course of formation of actomyosin there is a splitting of ATP, chemical energy to-rogo provides performance of mechanical work and partially dissipates in the form of heat.
In the based muscle (myofibrils and mezhmyofibrillyarny space) ion concentration To. it is supported below threshold size (10 - 7 L) as a result of their binding by the sarcoplasmic reticulum (SR) with the participation of special kaltsiysvyazyvayushchy) a squirrel — a kalsekvestrina. Binding To. it is carried out due to the energy released during the splitting of ATP by kaltsiyzavisimy ATP-ase. Thus, for accumulation To. in WEDNESDAY otvetstven the specific «calcic pump». At hydrolysis of 1 molecule ATP in cavities 2 ions of Ca are transferred 2+ in exchange for ions of Mg 2+ and, perhaps, also K+. Operation of «the calcic pump» is reversible. The possibility of stay of an intact muscle in the weakened state in the presence in it rather high concentration of ATP is explained by decrease in ion concentrations To. in the environment is lower than that limit, at Krom manifestation ATF-aznoy of activity and contractility of aktomiozinovy structures of muscle fiber is still possible. Bystry reduction of fiber at his irritation as a result of nervous impulse is a consequence of sudden change of permeability of membranes of the WEDNESDAY allowing ions To. to leave in a sarcoplasm. After attenuation of nervous impulse concentration To. in a sarcoplasm goes down as a result of operation of «the calcic pump» again and there is a relaxation of a muscle. To. is also the factor interfacing muscular contraction (the process consuming energy) to a glycogenolysis (the process making energy) since strengthening To. at reduction of a muscle activates a kinase of phosphorylase, key enzyme of regulation of a glycogenolysis.
Rhythmic alternation of reduction and relaxation of a cardiac muscle requires periodic change of concentration To. in a myoplasm — increase at reduction and decrease at relaxation. Three membrane structures participate in providing this mechanism: sarcolemma, C P and mitochondrions. Unlike a skeletal muscle, sokratitelny function of a myocardium depends on ion concentration To. in extracellular space.
The outer membrane of cells of a myocardium in the based state is impenetrable for external To. At depolarization of a membrane To. enters a cell and initiates the act of reduction. Thus, the act of reduction in a cardiac muscle is provided To., arriving from two sources — from WEDNESDAY and from extracellular space. In skeletal muscles To., arrived from WEDNESDAY, practically provides sokratitelny activity completely, and outside To., entered a cell during depolarization of its membrane, plays a role of «priming»; in a myocardium dependence of muscular contraction from extracellular To. is more considerable. Mitochondrions can take part in accumulation To. at relaxation of a myocardium, but use of mitochondrial fund K. in further functioning of a muscle it is complicated.
To ions To. the exclusive role in regulation of a tone of a sympathetic and parasympathetic nervous system belongs. To. increases reflex irritability of a spinal cord and the center of salivation. If potassium raises a tone of a parasympathetic nervous system, then To. possesses sympathicotrope action. Action To. on fabric it is shown in change of their trophicity, intensity of oxidation-reduction processes and in other reactions connected with formation of energy.
Change of concentration To. in the liquid washing a nervous cell significantly changes permeability of its membrane for potassium ions and especially for ions of sodium (see. Membranes biological ), and lowering of the level To. causes increase in permeability of a membrane for Na + and increase in excitability of neuron. Strengthening To. exerts the stabilizing impact on a membrane of a nervous cell.
To. the important role in processes of synoptic transfer belongs. In particular, the role of calcium in the processes connected with synthesis and allocation by nerve terminations of substances mediators is established (see. Mediators ). The special attention is deserved by influence To. on exchange of acetylcholine. This mediator is formed of acetate and sincaline in the presence of ATP and ions To. Jonah K. join in the reactions connected with exchange of acetylcholine as well as the factor activating secretion of acetylcholine nerve terminations during the passing of nervous impulse. Existence of ions To. it is necessary for implementation of reaction between acetylcholine and a receptor. Besides, To. exerts direct impact on permeability of a postsynaptic membrane for potassium ions and sodium.
In days the adult shall receive with food from 800 to 1100 mg of K. V bigger quantity To. children (from 1000 mg a day up to 7 years and apprx. 1400 mg in 14 — 18 years), pregnant women (1500 mg a day) and nursing mothers need (1800 — 2000 mg a day).
To. treats difficult assimilable elements. The connections K getting with food into a human body. are almost water-insoluble. Under the influence of acid contents of a stomach they partially turn into soluble compounds, but in view of insignificant absorbability To. in a stomach this transition of essential value has no.
Alkaline condition of a small intestine promotes formation of difficult assimilable connections K., and only impact on them of bile acids allows to translate To. in an assimilable state. Most intensively To. it is soaked up in duodenal and lean guts of hl. obr. in the form of monobasic salts phosphoric to - you.
Comprehensibility To. depends also on its ratio with other components of food and first of all — with fats, magnesium and phosphorus. It is established that the greatest number To. it is soaked up when it is the share of each gram of the fat entered with food apprx. 10 mg To. Disturbance of this proportion towards reduction or increase has equally an adverse effect on assimilation To. organism. At insufficient intake of fat few calcic salts fat to - the t giving soluble complex compounds with bilious to-tami are formed. At excessively greasy food is not enough bilious to - t to transfer all calcic salts fat to - t to a soluble state, and considerable part K. it is allocated with a stake (normal with a stake it is allocated 500 — 800 laid down To. in days).
Allocation To. depends also on character of food. Food with dominance in a diet of products with acid reaction of the environment (meat, groat dishes, bread, etc.) leads to allocation To. with urine (norm — 100 — 300 mg a day). At dominance in a diet of products with alkali reaction (abundance of dairy products, fruit and vegetables) To. the hl is allocated. obr. with a stake.
On absorption To. negatively excess of magnesium and potassium in food which compete with To influences. for bilious to - you therefore the amount of magnesium in diets shall make 1/2 — 3/4 number
of K. Osobenno the important factor influencing absorbability To., the quantity in food of phosphates is. Excess of phosphorus involves the increased formation of the three-basic phosphate To., which, almost without reacting with bilious to-tami, it is not transferred to a soluble state and not acquired by an organism. Increase in content of phosphorus in food worsens calcic balance, reducing its absorption and increasing removal from an organism. The ratio is considered physiologically normal To. and phosphorus in food 1: 1,5 or 1: 2.
Sharply negative influence on absorbability To. organic to - you, especially inozitfosforny to - that, contained in significant amounts in cereals and in products of their processing, and oxalic to - that, being a part of a sorrel and spinach render some. These to - you form with To. water-insoluble and absolutely not assimilable connections.
Process of ossification in the growing organism proceeds normally only at preservation of an optimum ratio To. and phosphorus in food. The regulator of this ratio is vitamin D which establishes an optimum ratio between To. and phosphorus in blood. Since at adults processes of ossification proceed less intensively, than at children, in their fabrics there is always a reserve To. and phosphorus therefore requirement at them for vitamin D is less. At the phenomena of calcic insufficiency adults under the influence of vitamin D have a delay To. in an organism irrespective of its contents in food.
At disturbance of calcic balance towards its reduction the reabsorption sharply raises To. from its depot in an organism. Endogenous To. it is removed went to a gleam. - kish. a path with secrets of all digestive glands. Its contents in a secret of parotid sialadens and in juice of a pancreas is especially high.
In complex process of regulation of calcic exchange the important role belongs to a liver. With bile inorganic compounds K are emitted. Disturbance of biosynthesis bilious to - t and other organic matters which are emitted with bile leads to formation of slaborastvorimy salts K., what is one of a factor of developing of cholelithiasis. Disturbance of homeostatic function of a liver affects activity of kidneys. Suppression of barrier function of a liver leads to the expressed disturbance of exchange To. in kidneys, to development of an urolithiasis. At atrophic cirrhosis concentration of blood proteins decreases that leads to reduction of quantity To., connected with protein, at the same time intensity of filtering increases To. through balls of kidneys.
Kidneys perform important function in exchange K. Rol of kidneys decides first of all by their participation in allocation on urine ionized To. and its diffusing connections. At the same time formation of connections K. with proteins and other high-molecular organic compounds interferes with its free diffusion through a membrane barrier of renal balls. In this regard the most part To. it is brought out of an organism not with urine: renal removal To. makes about one quarter of total quantity To., brought out of an organism. Kidneys quickly react to rejections of the contents To. in blood. Sensitivity of renal system to changes of concentration To. in blood the hl is defined. obr. the fact that kidneys are the most important place of application of kaltsiyreguliruyushchy action of humoral factors, first of all parathyroidin (PTG) — hormone of epithelial body (see. Parathormone ), a calcitonin (KT) — hormone of the parafollicular device of a thyroid gland (see. Kaltsitonin ) and vitamin D (see. Calciferols ).
At action of PTG concentration increases To. also the content of phosphorus in a blood plasma decreases. PTG and vitamin D work synergistically. The hypercalcemia caused by introduction by PTG is connected with increase in cellular activity of osteoclasts and the strengthened resorption of a bone caused by it. The bone is the main place of application of PTG. Under the influence of PTG there is a rassasyvaniye of a bone tissue due to dissolution of both mineral, and organic components of a matrix of a bone. PTG strengthens a reabsorption To. in renal tubules. At a lack of PTG the hypercalcuria develops. Under the influence of PTG absorption amplifies To. from intestines. Secretion of PTG sharply amplifies at a hypocalcemia. The antagonist of PTG concerning influence on exchange To. KT is. Secretion of KT increases with strengthening To. in a blood plasma. At action of KT in blood contents decreases To. and number of osteoclasts; osteoporosis is warned. KT prevents calcification of heart, kidneys and other bodies and promotes positive calcic balance in bones. At introduction of KT release of phosphorus kidneys amplifies. Normal secretion of KT becomes especially particularly important from the point of view of maintenance of calcic balance of the periods of starvation, a lactation, a long immobilization of patients, hypodynamias.
Regulation of exchange To. PTG and KT is connected with effect of hormones of a hypophysis, bark of adrenal glands and a thyroid gland. On exchange To. also glucocorticoids and mineralokortikoida have significant effect. At hyperfunction of adrenal glands removal amplifies To. with urine and a stake. Glucocorticoid hormones weaken gipokaltsiyemichesky influence of KT. Under the influence of somatotropic hormone along with strengthening of protein synthesis and delay of removal of phosphorus, nitrogen and sodium absorption increases To. in intestines. The last is caused by stimulation of formation of citrate which is one of important factors of system of transport To. The growth hormone has significant effect not only on bone, but also on other body tissues. Maintenance of a calcic homeostasis is coordinated by c. N of page and century of N of page. The special part in the central regulation of calcic exchange is assigned to gipotalamo-pituitary system. The last exerts impact practically on all closed glands, first of all — on parathyroid and thyroid. A certain part is assigned to cells of an epiphysis. Physiologically active agents emitted by these cells, first of all serotonin influence exchange To.
Changes of contents To. in a blood plasma are shown in the form of a hypercalcemia or a hypocalcemia. Normal the blood plasma contains 8,5 — 12,0 mg of % To., children (newborns) have 7,5 — 13,9 mg of %. Syndrome hypercalcemias (see) it is shown by a growth inhibition, anorexia, vomiting, locks, thirst and a polyuria, hypotonia of muscles and a hyperreflexia. At severe forms the nephrocalcinosis and arterial hypertension comes to light. At a long hypercalcemia calcification of vessels of kidneys develops (see. Calcification ). At a hypercalcemia of any etiology the keratopathy and even calcification of a cornea of an eye develops. According to V. M. Bogolyubov, disturbances from c are sometimes observed. the N of page who are expressed in confusion of consciousness, a lethargy, spotty memory defects. On an ECG reduction of a tooth P, increase in duration of a piece of QT and a systolic indicator is noted.
Hypercalcemia arises at excess reception of salts K., at the increased absorption To. from intestines and at decrease in its removal through kidneys. The hypercalcemia meets at a number of diseases. So, it arises at the increased consumption of vitamin D due to excess absorption To. from went. - kish. path. The hypercalcemia often complicates a system sarcoidosis of bones and a multiple myeloma, being shown incidentally or constantly. At the same time also the increased absorption forms a basis of a hypercalcemia To. from went. - kish. path. The hypercalcemia often accompanies Itsenko's disease — Cushing, an acromegalia, a hypothyroidism of malignant tumors of a lung, mammary gland, testicles, kidneys, a gall bladder, stomach, especially when there are metastasises in a bone. The hypercalcemia is the main sign of a hyper parathyroidism. Only in rare instances, at the expressed acidosis, the hyper parathyroidism proceeds without hypercalcemia. At a hyper parathyroidism urinary tract quickly are surprised. Usually at all diseases proceeding with a hypercalcemia also the hypercalcuria comes to light. The exception is made by a hypercalcemia at a hyper parathyroidism and a multiple myeloma when the hypercalcuria is observed seldom. From the diseases which are not followed by a hypercalcemia, the hypercalcuria is observed at poisoning with beryllium, excess reception of corticosteroids, at a hepatolenticular syndrome.
Hypocalcemia it is clinically shown tetany (see), edges the wedge, the syndrome which is characterized by a condition of a hyperexcitability of a nervous system is. Diagnosis of a hypocalcemia is based on data of the anamnesis, results a wedge, and laboratory researches. The attention to existence in the past of convulsive attacks and to structure of the eaten food is paid. The diagnosis is confirmed by indicators of contents To. and phosphorus in blood. Concentration To., especially its ionized form, it is reduced, and phosphorus — it is raised.
The hypocalcemia is observed also at a hypoparathyroidism, at an idiopathic tetany (spasmophilia), at disturbance of vsasyvatelny ability went. - kish. a path owing to its defeat or insufficient biliation in intestines, at hron, a renal failure, at a diabetes mellitus, at Fankoni's syndrome — Albertini, a hypovitaminosis of D. At an idiopathic tetany the disease proceeds chronically, with aggravations during the spring and autumn periods. At the same time changes of a trophic order, a cataract, a vykrashivaniye of teeth, a hair loss are often observed.
Therapy hyper - and hypocalcemias is defined, as a rule, by a basic disease.
8 artificial radioisotopes K Are known.: 37 Sa (T1/2 0,17 sec.), 38 Sa (T1/2 0,66 of sec.), 39 Sa (T1/2 0,86 sec.), 41 Sa (T1/2 8*10 4 years), 45 Sa (T1/2 153 days), 47 Sa (T1/2 4,7 of day), 49 Ca (T1/2 8,5 min.), 50 Sa (T1/2 9 sec.).
Practical application was found 45 Ca having beta radiation with energy of 0,252 Mev and 47 Sa with a beta radiation of two energy (0,67 and — 2 Mev) and the gamma radiation with energy of 1,3 Mev accompanying 74% of disintegrations of this radionuclide.
45 Ca receive in the nuclear reactor at radiation stable To. neutrons. This radionuclide is widely applied as a radioactive label in medicine and in experimental medico-biol. researches during the studying of absorption To. in intestines and distributions it in an organism it is normal also of pathology, and also ways and the speed of removal To. from an organism at different ways of receipt. It is especially widely used 45 Ca during the studying of biochemistry of a bone, and also mechanisms of transplacental exchange. Tag 45 Ca is used also in metallurgy, in agriculture — for the solution of questions of the movement of moisture in the soil, lixiviation To. from the soil, assessment of ways of application of fertilizers, etc. Less often as a radioactive label apply 47 Sa, received on the accelerator. This radionuclide has that advantage that it 7 radiation give in to measurement easier, than beta radiation 45 Ca; besides, having shorter half-life, it is less toxic. In a method of the neutron activation analysis formation of other isotopes K is used., in particular 49 Sa.
Annual average admissible concentration in air of workrooms is established: for 45 Ca — 3,2*10 - 11 , for 47 Sa — 1,7*10 - 10 curie/l. Minimum significant activity in a workplace which is not demanding registration or obtaining permission of bodies State a dignity. supervision, for both radionuclides it is equal 10 mkkyur.
Drugs of calcium
Drugs K. apply to replacement therapy at deficit To. in an organism. At acute insufficiency To. (a tetany, a spasmophilia) they are used in a combination with PTG, at hron, insufficiency To. (rickets, osteomalacy) — with vitamin D. Insufficiency To. in an organism can arise at its big expense (growth, a lactation, pregnancy), and also at a feeding schedule with insufficient contents To. (potatoes, bread, meat). In these conditions drugs K. accept preventively or add to foodstuff. Because To. participates in a metabolism in a bone tissue and teeth, it is applied sometimes to improvement of an union of changes, prevention of caries, to prevention of osteoporosis etc.
Drugs K. apply at pulmonary, nasal, uterine and other bleedings, however treatment by drugs K. effectively only in that case when in an organism there is a deficit To., since usually in an organism it is enough To. for ensuring normal process of a blood coagulation. At transfusion of large amounts of stored blood (500 ml and more), in to-ruyu citrate is added (for prevention of coagulation), intravenous administration of drugs K is necessary., as the anions of citrate which are in a free look are capable to connect To. the recipient, therefore there can be hypocoagulation, weakening of action of the heart etc.
Drugs K. apply also at the states which are not connected with calcic insufficiency. To. affects c. N of page soothingly, in high doses it suppresses neuromuscular transmission. To. strengthens cordial activity, increases arterial pressure, reduces spasms of bronchial tubes and went. - kish. a path, tones up a uterus, reduces membrane permeability, working protivovospalitelno, protivoekssudativno, desensibiliziruyushche.
Drugs K. are applied at neurosises, migraine, headaches after a spinal puncture, complex treatment of epilepsy etc. In an experiment To. can weaken the spasms caused by analeptics (Corazolum, strychnine, etc.). To. can recover the lowered excitability of nervous cells when disturbances are connected with change of ionic balance. So, To. removes the oppressing influence of ions of magnesium on c. N of page. Introduction To. promotes recovery of functions of an organism after the general anesthesia, at intoxications neuroleptics and other substances, in the oppressing c. N of page. To. include in antishock liquids, apply in surgery to prevention of operational hypotension. In these cases its influence on cordial activity, arterial pressure etc. matters. A promoting effect To. use at the heart diseases which are followed by hypostases or weakening of a tone of a myocardium.
Drugs K. strengthen function of adrenal glands and increase the content of adrenaline in blood. They are applied at complex treatment of bronchial asthma. Antiallergic effect of drugs K. it is connected with their antiinflammatory action, stimulation of emission of adrenaline by adrenal glands, and also ability To. to reduce release histamine (see) at allergic reactions. On reaction antigen — an antibody To. does not influence. Drugs K. apply as antiinflammatory at complex treatment of pneumonia, pleurisy, endometritises etc., to prevention of postoperative inflammatory processes. As the desensibilizing means To. it is used at a small tortoiseshell, a Quincke's disease, a serum disease, a medicinal allergy. In these cases use of its drugs together with antihistaminic drugs since is rational. To. has no antihistaminic properties.
Drugs K. are applied to osmotherapy at wet brain, at a craniocereberal injury etc. To. reduces penetration of a liquid part of blood into fabrics, promotes outflow of liquid from fabric in blood.
To. activates reticuloendothelial system and phagocytal function of leukocytes. Its drugs use at complex treatment of infectious diseases.
Drugs K. malotoksichna, however at the high speed of their introduction to a vein intoxication can develop. At the same time there occurs fibrillation of ventricles of heart, later — cardiovascular insufficiency and damage of kidneys owing to intensive removal of K. Byli are described allergic reactions to administration of drugs K. different intensity. To. it is contraindicated at thrombosis, atherosclerosis and a hypercalcemia, at individual hypersensitivity to its drugs. To. it is necessary to apply carefully at treatment by cardiac glycosides which effect it strengthens.
Calcii chloridum, Calcii chloridum, CaCl 2 - 6H 2 O. Colourless, bitterish on taste, the hydroscopic, blurring on air crystals, well water soluble (4: 1), it is worse — in alcohol (1: 9); supports 27% of K. Mestno works annoyingly (1 — 2% solution), and in big concentration — nekrotiziruyushche (10 — 15% solution). Calcii chloridum is applied at all indications to a kaltsioterapiya. At purpose of Calcii chloridum inside he acts by the principle of acid-forming diuretics and therefore it can be used in certain cases for strengthening of a mocheotdeleniye.
Property of Calcii chloridum to cause necroses at intradermal or hypodermic introduction is used for reflex stimulation of trophic processes. It is entered vnutrikozhno for creation small - focal necroses in skin of a back, extremities etc. for receiving reflex reactions from the place of irritation (removal of postoperative contractures in the reflex way, treatment hron, inflammations, etc.). Calcii chloridum is applied as antidote at poisoning with fluorides and oxalates for the purpose of formation of not dissociating non-toxic connections K., not capable to be soaked up in intestines. Calcii chloridum is appointed inside and intravenously. Since. To. it is slowly soaked up from went. - kish. a path, its intravenous administration is most effective.
Inside solutions of Calcii chloridum use 5 — 10% (wash down with milk), and intravenously — 10% solutions (in ampoules 5 and 10 ml). Calcii chloridum is used for an electrophoresis. At introduction of Calcii chloridum to a vein there is a short-term caumesthesia, a heat arising at first in an oral cavity, and then extending on all body, bradycardia, nausea. These phenomena can be explained with the fact that To. promotes release of a histamine from fabrics. Use this feature of reaction to introduction of Calcii chloridum for determination of speed of a blood-groove.
Form of release: powder in well corked glass jars and in ampoules on 5 and 10 ml of 10% of solution. Store powder in the dry place.
Calcium gluconate, Calcii gluconas, calcic salt gluconic to - you:
White granular powder, is dissolved in cold (1: 50) and in a boiling water (1: 5), it is insoluble in alcohol; contains 9% To. Unlike Calcii chloridum, renders less expressed local irritant action. Resorptive action in comparison with Calcii chloridum is expressed more weakly and arises more slowly in connection with smaller content To. in drug. It is used inside, subcutaneously, intramusculary and intravenously. Therapeutic doses are 2 — 3 times higher, than at Calcii chloridum. It is intravenously entered in the form of 10% of solution. 2 — 3 times a day are inside used in powders and tablets on 2,0 — 5,0 g. It is applied also to an ionophoresis and an induktoforez. Side effects arise seldom.
Forms of release: powder, tablets on 0,5 g and ampoules on 10 ml of 10% of solution. Store in well corked container.
Calcium lactate, Calcii lactas, calcium lactate:
White flour of slabogorky taste, is poorly dissolved in a cold water (1: 20), in hot — it is easier; supports 13% of K. Primenyaetsya in the same cases, as Calcii chloridum, - but, unlike the last, does not possess local irritant action and does not cause acidosis, on the contrary, increases an alkaline reserve that is used for elimination of already developed acidosis. The gluconate since it supports more K. Upotreblyaetsya inside on 0,5 — 1,0 g or a table, spoons in the form of 5% of solution 2 — 3 times a day is more effective pharmacological, than calcium.
Forms of release: powder and tablets on 0,5 g.
Store in well corked container.
Calcium glycerophosphate, Calcii glycerophosphas, glitserino - phosphorus-calcium salt; mix alpha and beta isomers:
CaPO 3 - O-C 3 H 5 (OH) 2 - nH 2 O
inodorous White powder, slabogorky taste. Let's dissolve in divorced salt to - those, it is water-insoluble also alcohol.
Apply as fortifying and tonic at subnutrition, overfatigue, a nervous breakdown, rickets. Strengthens anabolic processes; an effective agent in drug is phosphorus
Appoint inside the adult 0,2 — 0,5 g, to children on 0,05 — 0,2 g to reception 2 — 3 times a day (it is frequent in combination with iron preparations, arsenic and with strychnine).
Forms of release: powder and tablets on 0,2 and 0,5 g, granules in bottles on 100 g.
Store in well corked container.
Calcium the carbonate besieged, Calcii carbonas praecipitatus, CaCO 3 , has antiacid properties — see. Swept .
Methods of definition of calcium in biological liquids
the General To. (ionized and proteinaceous and connected) in biol, liquids determine by straight lines and indirect methods.
Indirect methods consist in preliminary sedimentation To. (ammonium oxalate, hloranilaty, pikrolanaty) from the studied liquid; the most correct results receive at use of ammonium oxalate. After sedimentation To. define gravimetrically, titirimetric, colorimetric.
At gravimetric determination To. besiege (during the heating in the alkalescent environment) in the form of almost insoluble calcium oxalate. The deposit is left to stand not less than 2 — 3 hours, filtered, wash out several times 0,1 — 0,5% solution of ammonium oxalate, calcinated at 1000 — 1200 ° and weigh calcium oxide (the factor of recalculation of calcium oxide on calcium is equal to 0,7146). The method differs in labor input.
At titirimetric definition the deposit of calcium oxalate is dissolved in a chamois (Vaard's method) or in salt (Kramer's method — Tisdalla) to - those and released oxalic to - that ottitrovyvat, most often potassium permanganate. The visual estimate of results causes bad reproducibility of titirimetric methods (coefficient of variation >of 10%).
Direct methods are more exact since they exclude the mistakes connected with sedimentation of calcium and dissolution of a deposit. Methods of kompleksonometrichesky titration in the presence of metallindikator belong to straight lines (see. Kompleksonometriya ). As a complexon usually use EDTA or EGTA (etilenglikolbisaminoetiltetrauksusny to - that). At kompleksonometrichesky titration most often as the indicator purpuric acid ammonium salt is applied (see. Grinblatta-Hartmena method ). Solution of purpuric acid ammonium salt and calcium-mureksidny a complex — unstable connections. Visual establishment of a final point of titration is inexact. Therefore in a number of methods of titration with purpuric acid ammonium salt carry out photometric.
During the work with flyuoreksony as the indicator the amount of blood serum is reduced to 0,1 ml (100 mkl); at titration in a point of equivalence disappearance of fluorescence is noted. This method is offered in 1959 by the Bulgarian doctors E. Vichev and A. Karakashov.
More accurate decolourization is reached at use as indicators of acid chrome dark blue, a kaltsiona, Gidron of II, glyoxal - an encore - 2-oksianila, allowing to define also quantitatively To. without department of magnesium. Solutions of indicators are steady, behind an exception glyoxal - an encore - 2-oksianila.
From direct methods the most exact are colorimetric methods: alizaric, with metiltimolovy blue, with about-krezolftaleinkompleksonom, about glyoxal - an encore - 2-oksianilom.
Alizaric methods are sensitive, can be applied in micro option, but are labor-consuming.
The method of definition with metiltimolovy blue is also characterized by high sensitivity, stability of a calcic complex, however has a small interval of linearity of the calibration schedule (to 3 mmolya/l, i.e. to 12 mg of %).
During the definition of calcium with about - cresol phthalein complexon the color complex is quickly formed in alkaline condition, is stable for a long time, is not sensitive to temperature influences, but is insufficiently specific. For an exception of an interference of magnesium and influence of ions of heavy metals on definition To. enter into the list of au - cresol phthalein-kompleksonovogo of a reactant 8 oxyquinoline, potassium cyanide or sodium sulfate, sodium acetate, dietenolamin. The method yields well reproducible results: coefficient of variation of 1,9%.
Glyoxal - an encore - 2-oksianil forms with To. in alkaline condition the complex painted in red color. Intensity of coloring is directly proportional concentration To. Reaction is highly sensitive and specific. For stabilization of a color complex use methanol or methanol — acetone.
Flyuorimetrichesky methods (see. Flyuorimetriya ) are based on selective fluorescence of a complex of a kaltsein (flyuorekson) with To. also blood sera allow to work with ultramicroquantities (20 mkl).
Methods of flame photometry (see) for definition To. are insufficiently exact (coefficient of variation apprx. 5%). The interference of ions of sodium, proteins, carbonates, sulfates is difficult removable. Preparation of complex standard solutions, use of gas mixtures with high temperature of a flame is necessary.
The greatest advantages on analytical properties (sensitivity, accuracy, specificity) the method of atomic and absorbing has spektrofotometriya (see). It allows to define concentration To. up to 0,0001%. The method differs in big productivity. It can be used as a standard for assessment of reliability of other methods of definition To.
For the definition ionized To. apply ion-selective electrodes (see).
Gistokhim, methods of identification To. and its salts — see. Kossa ways .
Bibliography: Biochemical methods of a research in clinic, under the editorship of A. A. Pokrovsky, page of i 8, etc., M., 1969; Bogolyubov V. M. Pathogeny and clinic of water and electrolytic frustration, L., 1968, bibliogr.; Boldyrev A. A. Biochemical aspects of electromechanical interface, page 78, M., 1977, bibliogr.; Ivanov I. I., Korovkin B. F. and Pinayev of G. P. Biokhimiya of muscles, M., 1977; Materials on toxicology of radioactive materials, under the editorship of A. A. Letavet and E. B. Kurlyandskaya, century 6, M., 1968; Mashkovsky M. D. Pharmaceuticals, p. 2, page 79, etc., M., 1977; Metabolism of a myocardium, under the editorship of E. Chazov and Yu. Braunvald, page 178, M., 1975; Standards of radiation safety (NRB-76), M., 1978; P about m and N of e of N to about V. D. Physiology of calcic exchange, Kiev, 1975, bibliogr.; Todorov Y. Clinical laboratory trials in pediatrics, the lane with bolg., Sofia, 1968, bibliogr.; Calcium, phosphate and magnesium metabolism, ed. by B. E. C. Nordin, Edinburgh, 1976; Inborn errors of calcium and bone metabolism, ed. by H. Bickel a. J. Stern, Lancaster, 1976; The pharmacological basis of therapeutics, ed. by L. S. Goodman a. A. Gilman, L., 1975.
V. M. Bogolyubov; G. A. Avrunina (I am glad.), M. V. Komendantova (pharm.), S. P. Mikhaylova (mt. issl.).