[Somatotropin increases the rate of incorporation of thymidine into DNA and amino acids into proteins of thymocyte subpopulations isolated in a ficoll-urografin gradient from hypothyroid rats]. / Somatotropin povyshaet skorost' vkliucheniia timidiba v DNK i aminokislot v belki subpopuliatsii timotsitov, vydelennykh v gradiente fikoll-urografin, u gipotireoidnykh krys.

The summarized suspension of thymocytes was separated into subpopulations in the ficoll-urografin gradient density and 6 fractions of thymocytes were obtained. Experiments in vivo showed that under hypothyreosis incorporation of 3H-thymidine into DNA thymocytes, which were isolated in the ficoll-urografin density of 1.065, 1.071, 1.073 and residue is found to be increased than that of intact rats by 72, 35, 47 and 24%, respectively, and incorporation of 14C-amino acids into thymocyte proteins--by 44, 29, 37 and 45%, respectively. Somatotropin normalizes incorporation of the mentioned precursors into the corresponding biopolymers.

[Effect of exogenous somatotropin on the ultrastructure of somatotropic cells in hyperthyroid rats]. / Vliianie ékzogennogo somatotropina na ul'trastrukturu somatotropnykh kletok u gipertireoidnykh krys.

Marked ultrastructural changes indicating a decrease in the cell functional activity occur in the somatotropic cells of rats after chronic hyperthyroidism with 1-thyroxin. Exogenous somatotropin produces no effect on these ultrastructural changes.

[Effect of somatotropin on cathepsin D in the liver of hypo- and hyperthyroid rats]. / Vliianie somatotropina na aktivnost' katepsina D, v pecheni gipo- i gipertireoidnykh krys.

In experiments on albino male rats the dependence of the cathepsin D activity on the thyroid hormone- and somatotropin levels in the organism was studied. It was demonstrated that the total cathepsin D activity in the liver of hypothyroid rats is lowered by 37% and that of hyperthyroid animals is augmented by 63%. Somatotropin injected to intact rats within 10 days in doses of 0.5 mg/100 g body weight enhanced the total enzyme activity by 19%. Hormone injection to hypothyroid animals returns to the normal cathepsin D activity, whereas in hyperthyroid rats the enzyme effect is significantly lowered under hormone action. Protein content in the nucleus-free homogenate of the hypothyroid rat liver does not differ from that of intact rats and is increased by 27% in hyperthyroid animals. Exogenous somatotropin returns to normal protein content in hyperthyroid rats.

[Somatotropin-synthesizing activity of the in vitro cultured adenohypophyses of intact, hypo- and hyperthyroid rats]. / Somatotropinsinteziruiushchaia aktivnost' kul'tiviruemykh vne organizma adenogipofizov intaktnykh, gipo- i gipertireoidnykh krys.

Somatotropin-synthetizing activity of the adenohypophyses cultivated in vitro in eu-, hupo- and hyperthyroid rats was investigated. The most pronounced persistence of the activity (89%) within 12 days is seen in the adenohypophyses of hypothyroid rats and less evident (41%) in the adenohypophyses of hyperthyroid animals in comparison with that of euthyroid rats (66%). The activity rise in the adenohypophyses of euthyroid hypothyroid rats is observed by the 6th day of cultivation, being more pronounced in the adenohypophyses of hypo- than euthyroid animals. The adenohypophyses cultivated in vitro in hypo- and hyperthyroid rats may serve as models for studying the adenohypophyseal somatotropic function disorders in hypo- and hyperthyroses.

[Somatotropic function of the adenohypophysis in hyperthyroidism]. / Somatotropnaia funktsiia adenogipofiza pri gipertireoze.

Changes in the adenohypophyseal somatotropin function and the site of their origin were studied in experimental rats with hyperthyrosis. It was determined that the adenohypophyseal somatotropin content and biosynthesis were sharply reduced. After repeated somatotropin injections these indices remained unchanged. In vitro the somatotropin-releasing activity of the hypothalamic extracts off hyperthyroid rats is enhanced, whereas somatotropin release into the medium, obtained from the adenohypophyses of hyperthyroid animals, is lowered under the extract effect. It is concluded that a decrease in the adenohypophyseal somatotropin function is caused by loss of somatotropic cell sensitivity to the action of the hypothalamic regulation factors.

[Effect of somatotropin on the activity of mitochondrial alpha-glycerophosphate dehydrogenase in the liver of rats with hypo- and hyperthyroidism]. / Vliianie somatotropina na aktivnost' mitokhondrial'noi alpha-glitserofosfatdegidrogenazy v pecheni krys s gipo- i gipertireozom.

The activity of mitochondrial alpha-glycerophosphate dehydrogenase in the liver of rats with hypothyrosis (two weeks after total thyroidectomy) is 36% of the normal level; in rats with hyperthyrosis (three weeks after subcutaneous implantation 2 mg of l-thyroxin on a kaolin base) it is 7.4 times as high. Bovine somatotropin (0.5 mg per 100 g of body mass) injected subcutaneously for 10 days has no effect on the enzyme activity in intact rats and in rats with hypothyrosis. In animals with hyperthyrosis somatotropin produces a 37% decrease in the enhance activity of the enzyme. Somatotropin fully normalizes a 25% increased amount of protein in the liver mitochondrial fractions of rats with hyperthyrosis.

[Ultrastructural changes in the thyro- and somatotropes of hypothyroid rats as affected by exogenous somatotropin]. / Ul'trastrukturnye izmeneniia v tireo- i somatotrofakh gipotireoidnykh krys pod vliianiem ékzogennogo somatotropina.

The state of somatotropic and thyrotropic adenohypophyseal functions of thyroidectomized rats after chronic injections of bovine somatotropin was studied. The adenohypophyseal somatotropin content increased by 22% per gland. The blood serum immunoreactive thyrotropin concentration was 0.925 +/- 0.063 microgram/ml in intact animals, 3.99 +/- 0.74 microgram/ml in thyroidectomized- and 1.27 +/- 0.19 microgram/ml in thyroidectomized rats, given somatotropin. According to electronic microscopy, hypothyrosis is characterized by an elevated functional somato- and thyrotrop activity, markedly decreased after somatotropin injection.

[Action of thyroid hormones and somatotropin on the free radical, iron-sulfur protein and cytochrome P-450 state in the liver]. / Vozdeistvie tireoidnykh gormonov i somatotropina na sostoianie svobodnykh radikalov, zhelezosernykh belkov i tsitokhroma P-450 v pecheni.

The state of free radicals, iron-sulphuric proteins and cytochrome P-450 was determined in hypo- and hyperthyroid rats by means of EPR method. It was shown that EPR signal of cytochrome P-450 was increased in the liver of thyroidectomized rats, characterized by somatotropin deficiency and delayed metabolism. It decreased under the action of exogenous somatotropin both in intact and in thyroidectomized animals. Cytochrome P-450 was lowered in hyperthyroid rats, characterized by intensified oxidative processes without signs of the enhanced hepatic growth. The feedback between the intensified hepatic oxidative processes and the activity of cytochrome P-450-dependent multipurposeful oxidases is suggested.

[Determination of somatotropin and prolactin by dodecyl sulfate polyacrylamide gel electrophoresis]. / Opredelenie somatotropina i prolaktina dodetsilsul'fat-élektroforezom v poliakrilamidnom gele.

Definite separation of somatotropin and prolactin using sodium dodecylsulphate polyacrylamide gel electrophoresis takes place in continuous systems with pH 7.0-7.2 containing acetate or chloride monovalet anions; substitution of the ions by polyvalent phosphate or borate anions interfered with the separation. The hormones precipitated by trichloracetic acid may be separated and quantitatively determined after dissolving in the weak alkaline solutions. The hormones are distinctly separated from serum proteins and may be quantitatively determined in media containing up to 15% of serum.

[Somatotropin-releasing activity of rat hypothalamus with hypo- and hyperthyroidism]. / Somatotropinvysvobozhdaiushchaia aktivnost' gipotalamusa krys pri gipo--i gipertireoze.

The somatotropin-releasing activity of rat hypothalamus was studied in the experiments in vitro incubating of adenohypophysis with the hypothalamic extracts or the whole hypothalamus and serotonin. The studied activity is shown to be increased in the thyroidectomized and hyperthyroid rats. Exogenic somatotropin prevents this increase. A conclusion is drawn that a link of hypothalamic adenohypophysotropic hormones of the regulatory system of the somatotropic function is not an area of the specific disturbances with hypo- and hyperthyroidism which might lead to hyposomatotropism.

[Serotonin formation in the hypothalamus of thyroidectomized rats under the influence of exogenous somatotropin]. / Utvorennia serotoninu v hipotalamusi tyreoïdektomovanykh shchuriv pid vplyvom ekzohennoho somatotropinu

The content of serotonin in hypothalamus of thyroidectomized rats is twice as low on the 5th day and twice as high on the 14th day after the operation as in the intact animals. Specific radioactivity of serotonin after subarachnoid administration of tryptophan-14C an hour before killing is twice as high on the 5th day and twice as low on the 14th day. Exogenous somatotropin prevents from the mentioned changes on the 5th day. A conclusion is drawn that the changes in serotonin metabolism in the hypothalamus of rats after thyroidectomy is mainly determined by the changes in the level of somatotropin in the organism.

[Separation of adenohypophysis hormones by electrophoresis on a dodecyl sulfate-polyacrylamide gel]. / Rozdilennia hormoniv adenohipofizu elektroforezom u dodetsylsul'fat-poliakrylamidnomu heli

Zones of somatotropin, prolactin and subunits of adenohypophysis glycoproteid hormones are identified in dodecyl sulphate-polyacrylamide gel after electrophoretic separation of these hormones in the tris-acetate system; The method is suitable for a quantitative determination of somatotropin and prolactin in adenohypophysis.

[Effect of exogenous somatotropin on the somatotropic function of the adenohypophysis in thyroidectomized rats]. / Diia ekzogennoho somatotropinu na somatotropnu funktsiiu adenohipofizu tyreoïdektomovanykh schuriv

Exogenic somatotropin increases the body weight gain in the inverse dependence on the taken dose and decreases the weight of the adenohypophysis in direct dependence on the dose in thyroidectomized male rats. The content of somatotropin in the adenohypophysis and incorporation of labelled amino acids into the adenohypophysis rises under the effect of exogenic somatotropin. But when the dose of the latter is increased, these indexes drop.

[Autoregulation of the somatic function of the adenohypophysis in intact and thyroidectomized rats]. / Autoreguliatsiia somatotropnoi funktsii adenogipofiza u intaktnykh i tireoidéktomirovannykh krys

Experiments conducted on male rats showed exogenous STH (2 mg daily for 10 days, subcutaneously) to cause a reduction in the STH content in the adenohypophysis and in the incorporation of labeled amino acids into the SHT in vitro both in intact and in thyroidectomized animals. Exogenous STH somewhat normalized the increase in body weight and the weight of the adenohypophysis of the thyroidectomized animals. A conclusion was drawn that autoregulation of the somatotropic function of the adenohypophysis persisted under conditions of a marked thyroid hormone deficiency.

[Separation of the hormones of the adenohypophysis of rats by use of electrophoresis in polyacrylamide gel in the presence of sodium dodecyl sulfate]. / Rozdilennia hormoniv adenohipofizu shchuriv z dopomohoiu elektroforezu v poliakrylamidnomu heli za naiavnosti dodetsylsul'fatu natriiu

A comparative study of rat adenohypophysis extract and its alcohol fractions was performed by two variants of the method of electrophoresis in polyacrylamide gel: at pH 9,5 and with the presence of sodium dodecyl sulphate at pH 7.2. With the presence of sodium dodecylsulphate four protein zones are found which in the order from the anode towards the cathode are identified as hemoglobin, somatotropin, lactotropin and albumin. It is shown that the somatotropin zone after the extract separation at pH 9.5 is inhomogeneous and consists of somatotropin and hemoglobin.