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Biomedical subjects

G V Valueva

Publications and source records attributed to G V Valueva.

At least 37 records · Page 2Linked to original sources
PubMed1980

[Effect of thyrotropic hormone on the membrane potential of thyroid gland cells and thyroid hormone secretion with aging].

Effect of thyrotropic hormone (TTH) on membrane potential (MP) of thyroid cells and thyroid hormone secretion was studied in experiments on male rats of two age groups (7--12- and 27--32-month-old animals). It was found that during the first 3 hours after TTH administration (5 U/100 g i. v.) the depolarization of secretory cell membranes of adult rats was done pronounced and developed more rapidly than in old ones and that an increase in free thyroxin (T4) correlation with MP changes with time. In a dose of 0.5 U/100 g TTH caused a significant rise in T4 secretion only in old rats. The cAMP level in the thyroid gland declined with aging. In a dose of 5 U/100 g TTH provoked a significant increase in the cAMP content in adult rats and had no effect on its content in old ones. A relationship between the MP level of thyroid secretory cells and thyroid hormone secretion is discussed.

Age Factors↗
PubMed1978

Metabolism of thyroid hormones during aging.

The paper presents experimental data on extrathyroidal metabolism of thyroid hormones in rats of various ages (1.5--32 months):: T4-131I distribution in an organism, indices of T4 and T3 kinetics, tissue deiodinative capacity, formation of T4 tissue metabolism products and their clearance from cells and organism, T4 binding with tissue proteins. Essential changes in T4 peripheral tissue metabolism have been found with aging: T4 binding by tissues is decreased; T4 distribution space and metabolic clearance are increased; 125I clearance with urine is decreased; T4 half-time in blood remains unchanged; tissue deiodinative capacity is enhanced. Indices of T3 peripheral metabolism in old rats remain unchanged. All these findings result in shifts of the T4/T3 ratio in favour of the latter and in invariability of its content in tissues, alongside with a decrease of functional activity of the thyroid gland with aging.

Aging↗
PubMed1978

[Interaction between the hypothalamo-hypophyseal system and the thyroid gland during different age periods].

Age peculiarities of interaction of the hypothalamo-hypophysial system and the thyroid gland with consideration to direct and feed-back control were studied. Significant alterations appear in old age in the hypothalamo-hypophysial system and the thyroid gland at the level of direct and feed-back control; there is an increase of sensitivity of the thyroid gland tissue to TSH, and of the hypothalamus-hypophysis--to the T4 effect. This rise of sensitivity is largely determined by the activation of the T4 deiodination processes in the adenohypophysis. The reactive capacity of the thyroid gland and of the hypothalamo-hypophysial complex to the corresponding influence is decreased.

Age Factors↗
PubMed1976

[Age and the functional activity of the pancreatic insular apparatus].

A study was made of age peculiarities of the insular function of the pancreas and of the indices of insuline provision of the organism in rat under conditions of sugar loading. It was shown that, in spite of hyperinsulinemia and a higher rate of insuline release glucose release in old rats became worse; this testified to the development of a relative insuline insufficiency in animals of old age. Hyperinsulinemia in old rats coursed against the background of a decreased total blood insular activity and increased "factor of insulin inactivation". The development of a relative insuline insufficiency in old rats depended on both the insular and the non-pancreatic factors, leading to a decrease of the biological activity of insuline.

Age Factors↗
PubMedDate not supplied

[The hypothalamus-hypophysis-adrenal system in patients with lactorrhea-amenorrhea syndrome].

Function of the hypothalamo-hypophyseal-adrenal system was investigated in 23 patients with different types of the lactorrhea-amenorrhea syndrome. The basal levels and "stress secretion" of ACTH, cortisol and cyclic nucleotides, the circadian rhythm of ACTH and cortisol levels were determined by RIA. Noticeable disorders in the central and peripheral factors of this system and changes in the blood levels of cyclic nucleotides were observed in patients with the lactorrhea-amenorrhea syndrome.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

[The function of the hypothalamo-hypophyseal-adrenal system in Itsenko-Cushing syndrome].

Altogether 28 patients with adrenocortical tumors (corticosteromas and corticoandrosteromas) were examined using a radioimmunoassay to determine the concentration of corticotropin, cortisol, blood cyclic nucleotides, the circadian rhythm and time course of corticotropin and cortisol levels against a background of insulin hypoglycemia. In patients with Itsenko-Cushing's syndrome the basel level of cortisol was notably raised, that of corticotropin was sharply decreased. The circadian rhythm of the levels of corticotropin and cortisol was disturbed, a response of the hypophyseal-adrenal system to a stressor was suppressed. The concentration of blood cyclic nucleotides was increased, and these changes were dependent on the nature of adrenal pathology.

Adrenal Cortex Neoplasms↗