Role of estrogens in the regulation of composition of bile acids of the enterohepatic system in rats and monkeys with extrahepatic cholestasis

Analysis of the thin-layer chromatography and gas chromatography data on the free and conjugated bile acid contents in the blood leaving intestine, hepatocytes and bile of ovariectomized rabbits and monkeys with acalculous cholecystitis revealed a heterogeneity of bile acid distribution in these biological media and an uniformity of specific alterations manifested in increased glyco-conjugation, decreased free bile acids in hepatocytes and blood, decreased cholesterol level and reduced lithogenic index of the bile. Results obtained are indicative of involvement of the gonadal steroids and estradiol dipropionate in regulation of bile acid conjugation in liver and, therefore, in development of one of the early factors of the gallstone formation.     

Consumption of aquatic subsidies by soil invertebrates in coastal ecosystems

Routes of aquatic allochthonous inputs (aquatic subsidies) to detrital food webs are studied, as is the effect of aquatic subsidies on the functional and taxonomic structure of soil invertebrate communities in coastal ecosystems. The study took place in the coastal zone of an oxbow lake of the Pra River in the Oka Reserve. The results indicate a strong dependence of soil animals in the coastal habitats on aquatic subsidies. Isotopic analysis shows that aquatic resources enter soil food webs not only via predators feeding on flying insects or aquatic prey, but also via saprophages decomposing organic debris of aquatic origin. The contribution of aquatic subsidies to the energy balance of soil invertebrates decreases rapidly with increasing distance from the lake. The fraction of aquatic carbon in tissues of collembolans and saprophages is negligible already a few meters from the water edge. The dependence of predatory invertebrates on aquatic resources can be traced at somewhat greater distance (tens of meters).     

Hormonal activity of the hypophysis-gonadal system in male hamadryas baboons in relationship to their hierarchical position

Hierarchic status-dependent hormonal activity of pituitary-gonadal system was studied in an isolated group of hamadryas baboons. Testosterone level was higher in dominating males. The level of sex hormone was higher in aged animals with great muscle mass. No correlation was observed between hierarchic status of hamadryas baboon males and the blood level of luteinizing hormone.     

The normalizing effect of dalargin on the glucocorticoid and opioid levels of the blood in CBA and C57Bl/6 mice undergoing footshock stress]

Radioreceptor investigations showed that it is impossible to interpret changes in the activity of opioid receptor ligands of mu and delta types in plasma of mice under footshock stress (FSS) as activation or depletion of opioid system (OS). There occurred qualitative changes characterized by interstrain differences (ID). These are also typical for dynamics of development of FSS effects on blood corticosterone levels. Administration of dalargin diminishes qualitative and quantitative changes in OS function at different periods after FSS preventing early rise of corticosterone levels after the exposure. In spite of common features in dalargin action on opioid and steroid metabolism in mice of both strains, ID are also present.     

Effect of immobilization stress on the gonadotropic function of the hypophysis in male hamadryas baboons (Papio hamadryas)

The plasma levels of luteinizing hormone (LH) and testosterone were studied in intact and castrated male baboons exposed to 2- and 10-hour periods of immobilization. Presented data have shown that immobilization stress induced a marked decrease in LH concentration both in intact and castrated monkeys. Changes in LH concentration positively correlated with plasma levels of testosterone only during the experimental procedures. During three days after immobilization there was a sharp dissociation in the dynamics of testosterone levels remained low and LH returned to normal values. We can suggest that it is not absolute LH level that is responsible for the changes in testosterone secretion during the immobilization stress.     

Effects of ovariectomy on the composition of fatty acids of phospholipids in Java macaques with cholestasis

Bilateral ovariectomy carried out in Java macaques with simultaneous dosed ligation of common bile duct distally to duodenum in order to induce acalculous hepato-cholecystitis, does not alter the lithogenic index of the bile. Phospholipids present in enterohepatic organs and tissues (hepatocytes, enterocytes, chyme, blood and bile) of gonadectomized animals with hepato-cholecystitis acquire a specific fatty acid pattern which is characterized by prevailing palmitic, stearic and oleic acids, unaffected level of arachidonic acid and traces of essential linoleic acid.     

Circadian rhythms of androgen levels in the blood of male hamadryas baboons

Radioimmunoassay was used to investigate circadian rhythms of blood plasma testosterone, 5 alpha-dihydrotestosterone, androstendione and dehydroepiandrosterone in intact animals and in those preadapted for experimental conditions. Blood plasma of monkey demonstrated monophasic circadian rhythms in the levels of androstendione, dehydroepiandrosterone and 5 alpha-dihydrotestosterone, with the maximal values seen early in the morning and minimal values in the evening. Circadian rhythms of testosterone were opposite in character. The adaptation of monkeys for housing and experimental conditions was marked by an increase in testosterone and 5 alpha-dihydrotestosterone levels in the blood as well as by an insignificant elevation of the levels of androgens of adrenal origin, leading to the changes in circadian rhythms of steroid hormones.     

Erratum to: Experimental Search for New Means of Pathogenetic Therapy COVID-19: Inhibitor of H2-Receptors Famotidine Increases the Effect of Oseltamivir on Survival and Immune Status of Mice Infected by A/PR/8/34 (H1N1)

Journal of Evolutionary Biochemistry and Physiology -     

Leptin activation of mTOR pathway in intestinal epithelial cell triggers lipid droplet formation,cytokine production and increased cell proliferation

Accumulating evidence suggests that obesity and enhanced inflammatory reactions are predisposing conditions for developing colon cancer. Obesity is associated with high levels of circulating leptin. Leptin is an adipocytokine that is secreted by adipose tissue and modulates immune response and inflammation. Lipid droplets (LD) are organelles involved in lipid metabolism and production of inflammatory mediators, and increased numbers of LD were observed in human colon cancer. Leptin induces the formation of LD in macrophages in a PI3K/mTOR pathway-dependent manner. Moreover, the mTOR is a serine/threonine kinase that plays a key role in cellular growth and is frequently altered in tumors. We therefore investigated the role of leptin in the modulation of mTOR pathway and regulation of lipid metabolism and inflammatory phenotype in intestinal epithelial cells (IEC-6 cells). We show that leptin promotes a dose- and time-dependent enhancement of LD formation. The biogenesis of LD was accompanied by enhanced CXCL1/CINC-1, CCL2/MCP-1 and TGF-β production and increased COX-2 expression in these cells. We demonstrated that leptin-induced increased phosphorylation of STAT3 and AKT and a dose and time-dependent mTORC activation with enhanced phosphorilation of the downstream protein P70S6K protein. Pre-treatment with rapamycin significantly inhibited leptin effects in LD formation, COX-2 and TGF-β production in IEC-6 cells. Moreover, leptin was able to stimulate the proliferation of epithelial cells on a mTOR-dependent manner. We conclude that leptin regulates lipid metabolism, cytokine production and proliferation of intestinal cells through a mechanism largely dependent on activation of the mTOR pathway, thus suggesting that leptin-induced mTOR activation may contribute to the obesity-related enhanced susceptibility to colon carcinoma.