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Biomedical subjects

S M Ledovskaia

Publications and source records attributed to S M Ledovskaia.

10 recordsLinked to original sources
PubMed1989

[The role of the thymus in regulating the stromal cells responsible for the transfer of the hemopoiesis-inducing microenvironment in stress].

The role of thymus in the regulation of stromal elements, responsible for haemopoiesis inducing microsurrounding transfer of animals, subjected to 10-hours immobilization, was studied. The development of bone marrow hyperplasia and stimulation of functional activity of stromal cells, responsible for haemopoiesis inducing microsurrounding transfer, were shown to be thymus dependent processes during stress.

Animals↗
PubMed1975

[Morphological changes in the thyroid gland of rats during various phases of the estral cycle].

The functional state of the thyroid gland and the concentration of thyroid hormones in the peripheral blood were studied in 20 mature female albino rats during their estral cycle. Evaluation of the thyroid functional state was made according to data of histological, morphological (the diameter of folliculi, the height of the thyroid epithelium) and histochemical analysis (determination of NAD and NADP-dehydrogenase, succinatedehydrogenase, lactate dehydrogenase, peroxydase, acid and alkaline phosphatase) as well as biochemical determination of iodine bound with protein (IBP) in the blood plasma and investigation of the ratio of the parameters in question under conditions of the sex cycle. The cyclic changes of the morphological state of the thyroid gland attended by the phases of the estral cycle were revealed. The activation of the organ was observed in proestrus and estrus which was evidenced by high levels of activity of the enzymes under study, high concentration of IBP in the blood and increased height of thyreocytes. A decreased function of the thyroid parenchyma was observed at the period of metaestrus-diestrus.

Acid Phosphatase↗
PubMed1975

[Functional morphology of the adrenal cortex during the physiological rhythm of sex steroid synthesis].

A method of a quantitative histenzymological analysis was used for determination of the extent of participation of various zones of the adrenal cortex in provision of physiological rhythm of the steroid synthesis. The activity of 3beta-OH-steroid dehydrogenase, glucoso-6-phosphat dehydrogenase, NAD- and NADP-diaphorases, acid and alkaline phosphatases and non-specific esterase was investigated. The data of a histoenzymotological study were compared with the result of biochemical analysis of corticosteroids in the peripheral blood. Under physiological conditions intensification of steroidogenesis was realized by mobilization of individual groups of cells of the adrenal gland, not its whole parenchyma. Physiological rhythm of steroid synthesis was provided by an integrated function of all the zones; however, by duration and quantitative expression of the secretory activity a structural heterogeneity was revealed in the adrenal cortex.

11-Hydroxycorticosteroids↗
PubMedDate not supplied

[Pregnanediol excretion in the sexual cycle dynamics of white rats guinea pigs and hamsters].

A study was made of pregnandiol excretion with the 24-hour urine of albino rats, guinea pigs and hamsters at various phases of the esteral cycle. Excretion of metabolities of the principal hestagens (progesterone and 20-alpha progesterone) in the form of alpha- and beta-isomers of pregnandiol proved to be definitely cyclic in character. The periodicity of pregnandiol excretion in the three types of experimental rodents reflected the course of the synthesis and secretion of hestagens, with a delay for a cycle phase. The maximal excretion of both pregnandiol isomeres with the 24-hour urine was abserved in albino rats during the estrus and metestrus, and in guinea pigs and Cricetus auratus W.--during the estrus and diestrus.

Animals↗
PubMedDate not supplied

[Diurnal rhythm of carbohydrate, lipid and protein metabolism and 11-hydroxycorticosteroid secretion in rats].

The results of study of the rhythms of secretion of 11-OCS, synthesis and metabolism of glucose, formation of urea and esters of fatty acids in male rats in the course of 12 hours of the daily period are presented in this work. A definite rhythmic character and conjugation of the processes of corticosteroid secretion and carbohydrate, fat and protein metabolism were revealed. Participation of the adrenal cortex hormones (glucocorticoids) in the regulation of direction of the carbohydrate metabolism by the type of glycolysis, hexosomonophosphate way and gluconeogenesis is discussed.

11-Hydroxycorticosteroids↗
PubMedDate not supplied

[The character of functional connections in the endocrine system of female white rats and their transformation with age].

The authors studied the functional interrelations between the adrenal glands and the thyroid gland of female albino rats of various age groups. Blood content of 11-oxycorticosteroids and protein-bound iodine was determined. Analogous determinations were carried out in partial exclusion of the adrenal gland function (metapyron block) and of the thyroid gland function (6-methyluracil block). It is supposed that in the young sexually-mature female albino rats the functions of the adrenal glands and the thyroid gland were in direct relationship irrespective of the cyclic variations in the sex steroid secretion; with the advance of age this association became deranged.

11-Hydroxycorticosteroids↗