Youssef H. Functional characteristics of adrenal glands in vivo and in vitro in the ontogenesis of white rats

The object of study: age-dependent changes of secretion and steroidogenesis processes and histological structure of adrenal glands and their organo-typical cultures. Purpose: comparative study of functional and morphological characteristics of adrenal glands and their organo-typical cultures in the ontogenesis of white rats for revealing the terms of the beginning of involution processes development and mechanisms leading to these processes establishment. Methods of study: method of organo-typical cultivation, fluorimetric method of 11-OCS measuring, colorimetric method of determination of protein, cholesterol and cells viability, method of two-stage cryoconservation, light microscopy, histological analysis. Theoretical and practical results, novelty: comparative analysis of morphological and functional state of adrenal glands and their organ-typical cultures in the ontogenesis of white rats has been made. It has been established that with aging a decrease of adrenal glands relative mass and as a result a decrease of glucocorticoids secretion into blood plasma occur. The diminution of secretion is stipulated not only by the decrease of adrenal glands relative mass but also by age-dependent changes in the structure of adrenal glands. Since 6-months age in tissues of adrenal glands appearance of separate cells with the features of apoptosis is recorded. In old animals (12-24 months) groups of cells with the features of apoptosis and expressed disorganization of structure of fascicular zone are recorded. At first analogous data have been obtained for organo-typical cultures. It was shown, that secretory ability of cultures from tissues of old animals decreased for 17-20 % as compared with cultures obtained from tissues of young animals (1-6 months). The decrease of secretion correlated with the decrease of steroidogenesis processes, which manifested in lower utilization of exogenous cholesterol and in diminution of ACTH-stimulated secretion. At first it was proved that organo-typical cultures from tissues of old animals have less adaptive and reparative capacities. Field of application: human and animal physiology, biochemistry, cell physiology.