From Big Medical Encyclopedia

MESCALINE (Mescalinum) — psychodisleptic substance; the alkaloid which is contained in a small succulent cactus of Anhalonium Williamsii Lew. (Echinocactus Williamsii Lew.) this. cactaceous (Cactaceae), growing in desert and sandy places in Mexico and the nek-ry southern districts of the USA. 3,4,5-Trimetoksifeniletilamin; With 11 H 17 O 3 N:

Water white oil of alkali reaction, water-insoluble, well soluble in chloroform, benzene and alcohol. Easily forms well crystallizing salts.

In M.'s experiment causes in animals of change of conditioned defensive reflexes (in the beginning oppresses, then facilitates), rastormazhivat an agressive behavior and breaks control of the irritants inducing aggression. The oppressing M.'s influence on conditioned reflexes considerably amplifies in the conditions of an emotional stress. At animal M. exerts the activating impact on EEG, increases stage of latency of emergence of a medlennovolnovy and paradoxical dream. At introduction to cerebral cavities causes analgetic and anorexigenic effects in animals.

Repeated introduction of M. quickly (within several days) leads to development in animals of tolerance to M.'s action on c. N of page. At the same time decrease in sensitivity of animals not only to M., but also some other psychodisleptic substances, napr, to diethyl amide lysergic to - you and to N1N-dietiltriptamin (cross tolerance) is observed.

The m is well soaked up in blood at various ways of introduction and in significant amounts collects in the field of the axonal terminations of neurons of a cerebral cortex. It is metabolized with formation of inactive demetilprovanny products, and also several not identified substances.

It is supposed that in the mechanism of action of M. on c. I. the page matters ability to stimulate adrenergic and dofaminergichesky transfer of nervous impulses by strengthening of transition of noradrenaline from the connected form in free, reduction of its inactivation with participation catechol-au-methyltransferase, and also due to blockade of transport of dopamine through membranes of neurons.

Causes acute psychosis with disturbances of mental functions in the person M. M.'s influence on mentality of the person is known since old time. In the past the pieces of the cactus containing M., so-called «peyota» which are dried up in the sun or «meskla» (from the Mexican name of a cactus — «пейотль», «meskat»), and also the tinctures received from this cactus were used by Indian tribes as the intoxicating means during the religious practices.

For a wedge, pictures of meskalinovy psychosis are characteristic frustration visual, space, temporary and to a lesser extent acoustical, tactile, olfactory and flavoring perceptions. Illusions (see) and hallucinations (see) are bright, colourfully and are volume saturated, merge with reality, are mobile and quite often rhythmical. Assessment of a spatial relationship and perspective is complicated or fantastic. Also perception of a body changes, parts to-rogo seem distorted in sizes and proportions or divided. Changes of acoustical images are various — from elementary hallucinations (see) before polyphonic soundings. Smells and taste are felt saturated and in a wrong way. Images are involuntary and are characterized by change of rate of the movement. At touch avtomatizm the synesthesia (at irritation of one of analyzers of a hallucination arise in other sense body) is characteristic.

Euphoria is characteristic of emotional experiences; in nek-ry cases the alarm and fear appears. On any emotional background emergence of desire of suicide is possible. The thinking loses the sequence, a continuity. There is an impression of sounding of thoughts and their projection (it is frequent in visual objects or outside).

Plentiful sensual experiences develop against the background of detachment, an obezdvizhennost and lack of spontaneous motives though emergence of motor excitement is in rare instances possible. At the beginning of meskalinovy intoxication control and ability of a detached self-assessment of a state remains though difficult intellectual functions and the formulation of thoughts are complicated. At increase of intoxication ability to critically estimate the events and to distinguish real disappears. Communication with surrounding is broken, consciousness concentrates on subjective experiences. Nature of disturbances consciousnesses (see), arising under the influence of M., it is various — from an oglushennost to oneiroid. Further memoirs are incomplete, inconsistent, but are sensually bright. The endured illusions and hallucinations can repeat out of M.'s receptions in situations of not clear consciousness (including prosonochny states in many years after meskalinovy intoxication). Duration of meskalinovy psychosis — of several o'clock (at reception of pure alkaloid) up to several days (at reception of pieces of the cactus containing M.).

Also nek-ry somatovegetativny frustration are characteristic of a picture of meskalinovy intoxication (bradycardia, decrease in the ABP, expansion of pupils, dryness in a mouth, nausea), to-rye are weakened or disappear at repeated receptions of M., i.e. with development of tolerance. At an alcohol abuse and opiates tolerance to M. increases.

Repeated receptions of M. or the products supporting him are followed by development of a syndrome of dependence.

At acute poisonings of M. for stopping of psychotic symptomatology introduction of neuroleptics of a fenotiazinovy row or barbiturates is shown.

M use only in pilot studies. In the USSR M.'s use and other psychotomimetics on the person is forbidden.

See also Psychodisleptic substances .

Bibliography: Milstein G. I., etc. Psychotomimetics, L., 1971; Stolyarov G. V. Medicinal psychoses and psychotomimetic means, page 260, M., 1964; Brawley P. a. D u f f i e 1 d J. • The pharmacology of hallucinogens, Pharmacol. Rev., v. 24, p. 31, 1972, bibliogr.; € o h e n S. Psychotomimetic agents, Ann. Rev. Pharmacol, v. 7, p. 30 1, 1967, bibliogr.; R a z d a n R. K. Hallucinogenes, in book: Ann. reports med. ehem., ed. by G. K. Cain, p. 23, N. Y. — L., 1970.

BB. B. Drills, And. H. Pyatnitskaya.