[Effect of hyperprolactinemia of varying origin on paracrine relationships in rat testes]. / Vliianie giperprolaktinemii razlichnogo geneza na parakrinnye vzaimootnosheniia v semennikakh krys.

Light microscopy characteristics of mature rat testes were studied in control and hyperprolactinemia rats. The number of cells defined as granulocytes in interstitial regions adjacent to seminal ducts at stage VII and XII of spermatogenesis has been calculated. Normal deference difference between these parameters diminish in hyperprolactinemia. It is suggested that prolactin participates in intratesticular paracrine mechanisms regulation.

[Effect of gene db dose on the development of beta-cytotropic and immunotropic effects of long-term glibenclamide administration in C57BL/KsJY mice]. / Vliianie dozy gena db na razvitie beta-tsitotropnogo i immunotropnogo éffektov dlitel'nogo vvedeniia glibenklamida u myshei C57BL/KsJY.

The studies have revealed a modifying influence of gene db on the expressivity of damaging beta-cytotropic effect of long-term sulphanilamide therapy and on the development of autoimmune cell response to antigens of pancreatic islets. It is substantiated as promising to study a significance of individual genes and their doses in determining the variations of reactivity to beta-cytotropic and immunotropic effects of the chemical nature factors.

[The effect of glibenclamide on the spontaneous evolution of genetically determined diabetes mellitus in C57BL/KsJY db+/+db mice]. / Vliianie glibenklamida na spontannuiu évoliutsiiu geneticheski determinirovannogo sakharnogo diabeta u myshei linii C57BL/KsJY db+/+db.

The study was carried out on 25 mice of the mutant C57BL/KsJY line carrying the autosomal-recessive gene db (diabetes) in the homozygous state with basal normo- and hyperglycemia by the beginning of the treatment with glybenclamide (the latent and manifest stages of insulin-independent diabetes mellitus). It was found that long-term oral administration of the drug in the therapeutic dose (20 micrograms per mice a day for 3-3.5 months) enhanced the genetically determined disturbances of glucose homeostasis and the insulin-producing apparatus of the pancreas irrespective of the stage of spontaneous diabetes genesis. The development of the organ-specific autoimmune reactions directed to antigens of the pancreatic islands was found.

[Effect of mutant genes db(diabetes) and m(misty) on the severity of high-dose streptozotocin diabetes in C57bl/KsJY mice]. / Vliianie mutantnykh genov db(diabetes) i m(misty) na tiazhest' vysokodozovogo streptozototsinovogo diabeta u myshei linii C57bl/KsJY.

It is stated that high-dose streptozotocin diabetes is more serious in gene db-homozygous mice of mutant line C57BL/KsJY than in heterozygotes db +/+ m and mice M+/+m. Manifestation of spontaneous insulin-independent diabetes mellitus in homozygotes db decreases the level of hyperglycemic streptozotocin-induced reactions.

[The effect of irradiation on the development of streptozotocin diabetes in C57BL/KsJY mice heterozygous and homozygous for gene db (diabetes)]. / Vliianie oblucheniia na razvitie streptozototsinovogo diabeta u geterozigotnykh i gomozigotnykh po genu db (diabetes) myshei linii C57BL/KsJY.

In experiments with C57BL/KsJY mice carrying a mutant db gene at the heterozygous and homozygous states it has been found that db+/+db mice are much more sensitive to gamma radiation with respect to the survival rate. In homozygotes, in contrast to heterozygotes, irradiation with a dose of 6 Gy does not reduce the severity of the diabetogenic effect of low doses of streptozotocin.

[The effect of long-term glibenclamide administration on pancreatic beta cells and on autoimmunity indices]. / Vliianie dlitel'nogo vvedeniia glibenklamida na pankreaticheskie beta-kletki i nekotorye pokazateli autoimmuniteta.

It was found that administration of glybenclamide in the therapeutic dose to rats exerts the damaging effect on insulin-producing apparatus of the pancreas (inhibition of the secretory reaction of beta-cells, disturbance of their morphological structure, decrease of glucose tolerance test), initiates the development of lymphocellular infiltration of islands (autoimmune insulitis), increases the level of antibodies to blood serum DNA. The inverse temporal dependence between the appearance and degree of diabetogenic effects of chronic sulfanylamide therapy and changes in autoimmunity (the latters are characteristic of earlier treatment with the drug) can be traced.

[Sensitivity of the rabbit embryonal Leydig cells to the action of different pituitary hormones]. / Chuvstvitel'nost' kletok Leidiga zarodyshei krolika k deistviiu razlichnykh gormonov gipofiza.

Leydig cells reaction of rabbits testis to choriogonin action has been investigated during the prenatal period of ontogenesis. It has been found, that these cells sensitivity to the hormones studied has been detected at the early stages of embryogenesis. The specialization of Leydig cells response to choriogonin, thyrotrophin and prolactin in the process of prenatal period has been shown.

[Importance of db gene for the development of low dose streptozotocin diabetes in C57BL/KsJ mice]. / Znachenie gena db dlia razvitiia nizkodozovogo streptozototsinovogo diabeta u myshei linii C57BL/KsJ.

The paper is concerned with some data on the effect of the diabetic gene (db) on mouse sensitivity to streptozotocin (SC). Male mice aged 2-3 mos. of mutant C57BL/KsJ strain (genotypes: m+/+m, db+/+m, db+/+db) were used for investigation. Insulin-dependent diabetes mellitus was induced by intraperitoneal injections of streptozotocin at a daily dose of 40 mg/kg for 5 days. The structure and function of the insular apparatus were histologically assessed as well as by the blood level of insulin and glucose within 15 days after the start of the experiment. The earliest hyperglycemic reaction to SC was typical of mice, homozygous by the diabetic gene; they had normoglycemia at the time of treatment. In mice, heterozygous by the diabetic gene, a hyperglycemic reaction developed later after treatment. However by the end of the investigation it reached values which were typical of mice, homozygous by the diabetic gene, with basal normoglycemia. Mice, not carrying the diabetic gene, as well as homozygotes by this gene with basal hyperglycemia, possessed lesser sensitivity to SC. The expression of hyperglycemic reactions showed correlation with a degree of dystrophic changes and the development of lymphocellular infiltration in the pancreatic islets of mice with basal normoglycemia in low dose streptozotocin diabetes. The development of spontaneous hyperglycemia in homozygotes by the diabetic gene lowered their sensitivity to SC diabetogenic effects.

[Characteristics of thyrocyte multiplication in proliferating thyroid epithelium]. / Osobennosti razmnozheniia tirotsitov v proliferiruiushchem tireoidnom épitelii.

Although the thyroid parenchyma is characterized by high proliferative ability, mitoses in it are seldom observed. Earlier it was considered that the main type of thyrocyte reproduction was amitotic division. However, biochemical investigations of late showed that the thyroid parenchyma during rapid growth in tissue culture intensively incorporated thymidine, this being an evidence of DNA replication indicating mitoses. To overcome this contradiction we staged experiments on adult male rats. First, their thyroids were slightly activated with thyrotropin at small doses, then in 6-8 h (when the number of amitosis-like thyrocyte nuclei increased markedly) the thyroids were excised and after proper histological treatment their sections were subjected to hydrolysis in IN HCI for the releasing of thymidine from DNA. Then thymidine was stained with Schiff reagent and its amount determined by cytophotometry. All the experimental animals displayed thymidine level redoubling, which demonstrated an authentic DNA replication despite the failure of mitoses. Thyrocyte nuclei suffered narrowing or constriction in their middle or were separated into two daughter nuclei. Thus in these cases DNA replication coincided not with mitoses but with endomitosis, as far as the nuclear membrane in thyrocyte nuclei was preserved and chromosome spiralization and formation of achromatic spindle failed. The physiological role of endomitoses in the proliferation of the thyroid parenchyma was that they ensured its more rapid growth than that resulting from karyokinesis.

Influence of pituitary hormones (hCG, TSH, Pr, GH) on testosterone level and on the functional activity of the Leydig cell in rat fetuses.

One day after the cessation of treatment the Leydig cells of the fetuses of pregnant rats, treated between the 11th and 15th or the 16th and 20th days of gestation, reacted to pituitary hormones. This finding indicates that both the receptors and the postreceptor mechanisms were in operative state. The effect of the thyrotropic hormone (TSH) overlaps the effect of related gonadotropic hormone (hCG), although this effect becomes smaller from the 21st day. The parameters investigated - the spectrocyto-fluorimetrically measured RNA-DNA ratio and the plasma testosterone level - ran generally in parallel. Similarly to the above-mentioned hormones, prolactin also increased the testosterone level (though to lesser degree than hCG and TSH did), however, while it increased the RNA level but at the age of 16 days, it decreased it the age of 21 days. Somatotropin (GH) also increased somewhat the testosterone level; however, the effects of the two related hormones (Pr and GH) fell far beyond the effect of either TSH or hCG.

[Correlations between the functional activity and proliferation of the thyroid parenchyma. The proliferative forms of the parenchyma of the thyroid]. / O sootnoshenii funktsional'noi aktivnosti i proliferatsii parenkhimy v shchitovidnoi zheleze. Formy proliferatsii tireoidnoi parenkhimy.

Multiple thyroid adenomas formed by straight or coiled epithelial cords developed in experiments on adult male rats as a result of prolonged intermittent 6-MTU administration. Such epithelial cords could be sometimes observed in thyroid parenchyma regeneration after partial thyroidectomy. These cords originated from thyrocytes of the follicle epithelium. In the proliferating thyroid parenchyma DNA replication mainly terminated in endomitoses (previously reported data) which in thyrocytes of prismatic form resulted in their separation from proximal and distal daughter cells. Proximal daughter cells kept contact with the follicle lumen but distal ones lost it, hence their iodine uptake and origination weakened. Therefore, the biosynthesis of thyroglobulin decreased in cytoplasm of distal daughter cells but the formation of thyroalbumin increased. In consequence the distal daughter cells with this shift in protein biosynthesis underwent hypertrophy and further originated the proliferation of extra follicular epithelial cords. The formation of new follicles mainly took place with the differentiation of interfollicular islets separated from proliferating extrafollicular epithelial cords. Thyrotropin, the principal stimulator of hormonopoietic thyrocyte activity, did not necessarily influence the activation of thyroid parenchyma proliferative processes.

[Use of luminescence microspectral analysis for evaluating the synthetic activity of testicular incretory cells]. / Primenenie liuminestsentnogo mikrospektral'nogo analiza dlia otsenki sinteticheskoi aktivnosti inkretornykh kletok semennikov.

A study was made of the synthetic activity of Leydig's cells in the testes of rabbit fetuses at different stages of intrauterine development by the method of luminescent microspectral analysis and the results were compared with the level of testosterone determined by a radioimmunoassay in the blood plasma of these fetuses. The data obtained by both methods showed correlation. A conclusion has been made as to a possibility of the use of the luminescent microspectral method to study the synthetic activity of cells of the endocrine glands.

[Development of the rete testis in the prenatal ontogeny of rodents and effect of prolactin and thyrotropin on its cellular differentiation]. / Razvitie seti semennika v prenatal'nom ontogeneze nekotorykh gryzunov i vliianie prolaktina i tirotropina na differentsirovku ee kletok.

The development of rete testis in the rat, rabbit and guinea pig foetuses has been studied, as well as the influence of prolactin and thyrotropin on differentiation of its cells. It was shown that the rete testis tubules, as well as the seminiferous tubules develop from sex cords, which were derived from coelomic epithelium cells and gonocytes. The development of seminiferous tubules and rete testis was described at various stages of prenatal ontogenesis. Thyrotropin and prolactin exert different effects on differentiation of the rete testis cells: the former increases the mitotic activity of gonocytes and the latter increases that of epithelial cells and enhances degenerative processes in primary germ cells.

[Interrelation of prolactin and calcitonin]. / Vzaimootnosheniia mezhdu prolaktinom i kal'tsitoninom.

Intraperitoneal prolactin injection (3.5 U/200 g bw, daily, for 5 days) caused a marked rise in blood calcitonin concentration in female Wistar rats. It is common knowledge that exogenous calcitonin administration results in an obvious drop of blood prolactin level. Hence, the interrelation between anterior pituitary lactotropic function and blood calcitonin level may be regarded as a negative feedback, since prolactin activates calcitonin production and secretion, with the latter, in its turn, inhibiting adenohypophysial lactotropic function.