[Alteration of thyroid hormone secretion after long-term exposure to low doses of endocrine disruptor DDT].

Endocrine disruptors are exogenous substances that exhibit hormone-like action and consequently disrupt homeostatic action of endogenous hormones. DDT is the most common disruptor. The objective was to evaluate changes in thyroid hormone secretion after long-term exposure to low doses of DDT. The experiment was performed on male Wistar rats. The rats were given DDT at doses of 1.89±0.86 мg/kg/day and 7.77±0.17 мg/kg/day for 6 and 10 weeks. Dose dependent increase of serum total thyroxine, total triiodthyronine, and thyroid peroxidase was revealed after 6 weeks exposure. After 10 weeks free thyroxine secretion was reduced. Such alterations of the thyroid status are typical for iodine deficient goiter. The data obtained indicate that the main mechanism of DDT action includes disruption of thyroxine secretion by thyrocytes, but not inhibition of deiodinase activity and decrease of blood thyroid binding proteins.

[Novel concepts in biology of diffuse endocrine system: results and future investigations].

Diffuse endocrine system is a largest part of endocrine system of vertebrates. Recend findings showed that DES-cells are not neuroectodermal but have ectodermal, mesodermal, and entodermal ontogeny. The article reviews novel concept of diffuse endocrine system anatomy and physiology, functional role of DES hormones and poorly investigated aspects like DES-cell morphology, hormones secretion in normal and pathologic conditions. Further research of diffuse endocrine system has a great significance for biochemistry, morphology, and clinical medicine.

[Endocrine disruptors are a novel direction of endocrinologic scientific investigation].

Endocrine disruptors are exogenous anthropogenic chemicals (pesticides, herbicides, polychlorinated biphenyls, bisphenol A, polybrominated diphenyl ethers, phthalates and others), that are able to bind hormonal receptors of endocrine and other cells in vivo and act like hormones. These substances disrupt endocrine regulation of metabolism, reproduction and adaptive reactions of organisms and promote human and animal endocrine disorders.

[Outstanding problems of normal and pathological morphology of the diffuse endocrine system].

The diffuse endocrine system (DES)--a mosaic-cellular endoepithelial gland--is the biggest part of the human endocrine system. Scientists used to consider cells of DES as neuroectodermal. According to modem data cells of DES are different cytogenetic types because they develop from the different embryonic blastophyllum. So that any hormone-active tumors originated from DES of the digestive, respiratory and urogenital system shouldn't be considered as neuroendocrinal tumors. The basic problems of DES morphology and pathology are the creation of scientifically substantiated histogenetic classification of DES tumors.

[Actual problems of biology of pancreatic acino-insular cells].

Acino-insular cells are a distinct type of pancreatic cells sharing structural and functional features of both acinar and islet cells. They synthesize and secrete digestive enzymes and hormones. Novel concepts of the functional role of acino-insular cells and prospects for their further investigation are reviewed.

[Problems of experimental simulation of hypo- and hyperthyroidism].

This paper reviews main conventional and new experimental models of hypo- and hyperthyroidism. The authors propose classification of methods (physical, chemical, and biological) for modulation of thyroid activity and criteria for life-time and postmortem diagnosis of hypo- and hyperthyroidism. New approaches to simulation of diffuse toxic goiter in animals are considered, advantages and limitations of different models are compared.

[Thyroid gland development in Japanese quail embryos incubating in microgravity]. / Razvitie shchitovidnoi zhelezy u émbrionov iaponskogo perepela, inkubirovannykh v usloviiakh mikrogravitatsii.

The investigation of the progress of thyroid prenatal development in the Japanese quail has been first performed in the MIR microgravity environment. Development of thyroid glands in control and flight embryos was shown to pass same stages (trabecular and follicular). However, the flight embryos demonstrated retarded a development of the gland as compared to the control one. Slowing-down of thyroid organogenesis in the flight embryos is evidently related to retardation in formation of their blood system and a consequent decrease in blood inflow to the thyroid microcirculatory bed.

[Antifibrosis effect of modified forms of catalase and superoxide dismutase in experimental silicosis]. / Antifibroznoe deistvie modifitsirovannykh form katalazy i superoksiddismutazy pri éksperimental'nom silikoze.

The forms of catalase modified by treatment with dextran aldehyde were obtained and studied. Efficacy of the preparations containing native and modified forms of catalase and superoxide dismutase as well as their covalent bienzyme conjugate containing catalase-dextran aldehyde-superoxide dismutase was studied in rats with simulated silicosis. The preparations were administered into rats by means of inhalation and intraperitoneal injection. Positive protective effect exhibited a mixture of native enzymes and their covalent conjugate. The most pronounced additional effect was caused by the mixture of native catalase and superoxide dismutase as compared with modified preparation of superoxide dismutase. The preparation of bienzyme containing conjugate was less effective.

[Experimental research on the efficacy of terrilytin in silicosis]. / Eksperimental'nye issledovaniia éffektivnosti terrilitina pri silikoze.

Experimental silicosis was induced by quartz-containing dust administered intratracheally to Wistar male rats. Proteoclastic enzymes terrilytine was found to arrest pulmonary fibrosis, which was proved by inhibited development of silicotic granulomas and their lowered fibrosis. Terrilytine was most effective when inhaled in a dose of 0.08 PU per rat. Injected intraperitoneally, terrilytine in the dose elevated from 0.1-0.2 to 0.3 PU inhibited fibrosis developing in the presence of marked serous desquamative alveolitis. Incorporation of the enzyme in the cholesterol-lecithin liposomes prevents this side effect in the lungs. Liposomes injected intraperitoneally do not influence the development of pulmonary fibrosis in silicosis.

[The role of fibronectin in the development of fibrosis]. / Rol' fibronektina v razvitii fibrozov.

The structure, location, and function of fibronectin are reviewed on the basis of the data available in the literature. The contribution of fibronectin to the pathogenesis of granulomatous diseases, including pneumoconioses is shown in the paper. Formation of pulmonary fibrosis++ in pneumoconioses and its involvement of fibronectin are outlined in detail. The ways of further studies of this glycoprotein in occupational pulmonary diseases are also discussed.

[Basic achievements in the diagnosis and in the problems of the pathogenesis and clinical picture of respiratory organ diseases of dust etiology]. / Osnovnye dostizheniia v diagnostike, voprosakh patogeneza i kliniki zabolevanii organov dykhaniia pylevoi étiologii.

The article contains new data concerned with the respiratory pathologic processes caused by industrial aerosols of different compositions, as well as the mechanisms of their functioning and development. Current problems of occupational lung diseases' treatment are considered in this connection.

[Significance of morphofunctional assessment of tissue basophil reactions in prognostication of harmful effects of chemical substances]. / Znachenie morfofunktsional'noi otsenki reaktsii tkanevykh bazofilov dlia prognozirovaniia vrednogo deistviia khimicheskikh veshchestv.

The article contains a comparative analysis of experimental data on the assessment of the general toxicological, gonadotrophic effects and morphofunctional reactions of tissue basophils under the influence of 4-bromine-o-xylene, carbon disulfide and pyracryl. Established was the gonadotrophic action of pyracryl against the growing activity of tissue basophils manifested through increased infiltration and high-level degranulation in female rats' reproductive organs. Demonstrated was that, under the influence of low-intensity chemical factors, tissue basophils morphofunctional reactions were those of organ-related nature. The quantitative assessment of tissue basophils was proposed as an informative model for studies of selective (gonadotrophic) actions of low-intensity chemical substances.

[Tissue basophils in vascular plexuses of the lateral ventricles of the brain in humans and various mammals]. / Tkanevnye bazofily sosudistykh spletenii bokovykh zheludochkov golovnogo mozga u cheloveka i nekotorykh mlekopitaiushchikh.

By means of histological and histochemical methods cell composition of vascular plexuses in the lateral ventricles of the rats, dogs and man has been investigated. Besides ependymocytes, endotheliocytes, pericytes, myocytes in the microcirculatory bed, described in literature, tissue basophils (TB) have been revealed and what is more--only in dog and man. The most variable forms and localizations of TB are observed in vascular plexuses of the lateral ventricles of the human brain. The following varieties of TB can be defined: small with ortochromic granularity and large ones with abundant metachromic granularity. Sometimes degranulating TB occur. According to their localization they are divided into stromal (+interstitial++), perivascular subepithelial and intraepithelial. The variable TB localization in the vascular plexuses of the brain can probably demonstrate their participation in performing functions of the hematoencephalic barrier.

[Morphofunctional indices of the effects of pyracryl on the organs of female genital system in rats]. / Morfofunktsional'nye pokazateli vliianiia pirakrila na organy zhenskoi polovoi sistemy krys.

Morphofunctional indices of pyracryl (phosphate poly-2-pyridylethylmethacrilate) effecting reproduction system of Wistar rats have been studied. It has been shown that monthly administration of pyracryl in doses 1 mg/kg and 5 mg/kg lead to infiltration of mast cells and their pronounced degranulation and impairment of blood and lymph microcirculation. As far as gonadotropic effect is concerned, its parametres depend on the administration of pyracryl. Pyracryl in doses of 1 mg/kg stimulates folliculogenesis in ovaries, a dose of 5 mg/kg may cause expressed atresia of growing follicules and changes of oestrous cycle. It is suggested that biologically active substances of mast cells in female reproduction system play an important role in realization of gonadotropic effects of pyracryl.

[The reaction of the endocrine cells of the gastrointestinal tract in response to exposure to 3,6-dichloropicolinic acid]. / Reaktsiia éndokrinnykh kletok zheludochno-kishechnogo trakta v otvet na vozdeistvie 3,6-dikhlorpikolinovoi kisloty.

Silver-impregnated argentaffin cells both Ec, D1, G, P, S and K enteroendocrine cell types of rat gastrointestinal mucosa were investigated under light and electron microscopy after single oral administration of 3,6-dichloropicolinic acid. As a result, in pyloric-duodenal region Ec cells after a period of 1 hour had intensively secreted hormones. Ultrastructurally their cytoplasm and secretory granules were covered by expressed vacuolization. These data hypothetically elucidate the role of the endocrine regulations in developing barrier function of the gastrointestinal epithelium.

[Morphofunctional changes in the endocrine system of the small intestine after its proximal resection]. / Morfofunktsional'nye izmeneniia éndokrinnogo apparata tonkoi kishki posle ee proksimal'noi rezektsii.

The influence of 50% proximal resection of the small intestine on the intestinal endocrine system was investigated on white male rats. The quantitative changes of argyrophil and argentaffin cells correlated with their secretory activity changes. The opposite character of secretory function synchronization was revealed on the 7th and 30th days along the length of the small intestine (proximo-distal sinusoid phenomenon). The secretory function normalization of the endocrine system is carried out in the distal and proximal direction along the length of the small intestine.