From Big Medical Encyclopedia

FABRIC DETERMINATION (Latin determinatio restriction, definition; synonym: determination is histologic, determinancy, specificity of fabrics) — genetically caused high specificity of all properties of fabrics, including character of their differentiation kept under any conditions.

The term «fabric, or histologic, determination» was applied for the first time by N. G. Hlopin (1946) to designation of the specificity of fabrics which is expressed in their ability to form strictly certain differentiated structures and inability to turning into of fabric of other type (e.g., epithelial fabric never turns into connecting, muscular or nervous tissue). Etc. develops during ontogenesis (see); it is not identical at different stages of evolution. Degree Etc. raises with complication of the organization of animals. The mechanism of fabric determination is connected with permanent changes of processes of repression (blocking) and derepression (unblocking) of genes (see. Gene ).

Distinguish two forms Etc.: labile (probabilistic and statistical) and rigid (unambiguous). In the first case development of fabric has no strict focus and the unambiguous program. Depending on action of cells of factors, external in relation to a genome, the direction and the course histogenesis (see) can change. At the second form Etc. development of fabric is characterized by irreversible changes genome (see) and one-orientation of a differentiation of cells. Etc. and a dpfferentsirovka of cells act as two interconnected processes — at determination there is a programming of a certain way of development of cells, and during their differentiation the realization of this program is enabled — there are biochemical and morphological distinctions between different types of fabric cells.

Determination of fabric properties of cells happens at the level of synthesis of information RNA whereas the dpfferentsirovka of cells occurs at the level of broadcast of a genetic code (see) from molecule RNA on synthesizable tkanespetsifichesky molecules of protein.

Etc. defines not only a differentiation, but also all main manifestations of life activity of cells (their ability to a reproduction, intercellular interactions, adaptation opportunities). As Etc. otrazht high specificity of the properties of fabric remaining in any conditions, knowledge of its patterns is necessary for understanding of essence of a histogenesis, reactivity and an angenesis, their tumoral growth, hereditary pathology.

Bibliography: Zavarzin A. A. Chosen works, t. 4, M. — L., 1953; To l and-sh about in A. A. Gistogenez, regeneration and tumoral growth of skeletnomyshechny fabric, L., 1971; Knorre A. G. Embryonal histogenesis, L., 1971; B. V. Genetik's Grooms of development of vertebrata, M., 1980; Mikhaylov V. P. Classification of fabrics and the phenomenon of a metaplasia in the light of the principle of fabric determination, Arkh. annate., gistol. and embriol., t. 62, century 6, page 12, 1972; P e t of l e N - to about V. P., With t r at to about in A. I. and Khmelnytsky O. K. A determinism and the theory of causality in pathology, M., 1978; With t r at to about in A. I., Khmelnytskyi of O. K. and P e t of l e N to about Century. Morphological equivalent of function, M., 1983; Hlopin N. G. All-biological and experimental fundamentals of histology, L., 1946; Shchelkunov S. I. Philosophy of a cellular differentiation, L., 1977.

A. A. Klishov.