The participation of the striatum in the central regulation of gonadal hormonal function]

Intrastriatal corticotrophin-releasing hormone (CRH) was shown to induce a decrease in the plasma tectosterone concentration. Besides, the 6-OHDA pre-treatment completely prevented the suppression of plasma testosterone in response to intrastriatal CRH administration. The findings suggest that the striatum is involved in the extrahypothalamic regulation of the gonadal endocrine function.     

Monoaminergic innervation of the kidney of the carp (Cyprinus carpio L.)

By means of fluorescent-histochemical method distribution of monoaminergic structures has been studied in the sympatho-adrenal system of the carp (Cyprinus carpio L.) mesonephros. Catecholaminergic nervous fibers are revealed in the walls of adrenal and venous vessels and glomerular arterioles. In the glomerular capillaries they are not found. In the walls of the venous vessels, besides catecholamine-containing nervous fibers, chromaffin cells with long processes running along the vessel are observed. Some contacts of catecholamine-containing structures of the mesonephric vascular wall with the proximal and, very seldom, with distal parts of the nephron canaliculi are demonstrated. Structures containing indolamines are not revealed.     

Dynamics of hypothalamic CRH immune reactivity in active and passive rats in the course of development of behavioural depression

A possible relation between activity of the main CRH-producing centers of hypothalamus and depressive-like behavior of animals was studied. We used genetically selected strains--KHA (Koltushi High Avoidance) and KLA (Koltushi Low Avoidance) rats, demonstrating active and passive strategy of adaptive behavior in novelty situaltions, respectively. Rats were exposed to inescapable stress to develop a "learned helplessness". We observed considerable differences between two strains of animals in CRH-expression in parvo-, magno-cellular parts of the paraventricular nucleus and in the supraoptic nucleus in the course of behavioral depression development. Significant differences between control groups were seen only in paraventricular nucleus. On the 1st post-stress day in hypothalamus of KLA rats, we detected decreased CRH immune reactivity that remained unchanged up to the 10th day. In KHA rats, there were no notable changes of CRH expression in all studied nuclei. These findings, including previous results on different dynamics of behavioral changes and different hypothalamo-pituitary-adrenocortical system activity during development of depression in KLA and KHA rats, indicate that "learned helplessness" in these two groups of animals provides the model analogues of different types of depression. Besides, these findings indicate different implication of hypothalamus CRH-system in the behavioral depression development in rats with divergent strategy of adaptive behavior.     

Dopaminergic processes in the striatum mediating corticoliberin effect on behavior of active and passive rats

The action of intranasal corticotropin-releasing hormone (CRH) administration on open field behavior and striatal and hypothalamic levels of dopamine, noradrenaline and their metabolites has been studied in rats with different behavior strategies (KHA and KLA strains). In KLA rats, CRH administration resulted in increased locomotor and exploratory activity, while KHA rats demonstrated decreased that. The analysis of catecholamine levels did not detect any strain differences in hypothalamus, but in striatum the dopamine levels have been twice higher, while the metabolite levels (DOPAC and HVA) were significantly lower in KLA rats as compared to KHA rats. The CRH administration led to increased dopamine and noradrenaline levels in hypothalamus and decreased those in striatum in rats of both strains, but in KLA the decrease was more evident. It is probably a result of intensified mediator turnover induced by the neurohormone in KLA rats, as supported by a fact of increased dopamine metabolite levels in this structure.     

Corticosteroid hormones in pathogenetic heterogenety of post-stress depression

The role of corticosteroid hormones in post-stress depression progress and their usage for correction of this psychopathology was studied in active and passive Wistar rats. It was found that only passive individuals had sensitivity to corticosteroids and, among them, only adrenal gland hormones lead to corrections of post-stress depression.     

Influence of progesterone administration in early stage of development on morphometric parameters of the rat uterus

The aim of this study was to evaluate the effects of single injection of 0.5 mg progesterone in neonatal stage of development on morphometric parameters of the adult rat uterus. The results showed that there were no changes ofendometrial morphometry in respect to oestrous cycle in neonatal treated rats. Neonatal administration of progesterone decreased the myometrium thickness in oestrus and dioestrums owing to circular muscle layer, and disturbed sex steroids secretion during the oestrous cycle. These data suggest that neonatal administration progesterone reduces the endometrium sensitivity to sex steroids and produces the myometrium atrophy.     

Prediction of the three-dimensional structure of aflatoxin of Aspergillus flavus by homology modelling

Aflatoxins are polyketide-derived secondary metabolites produced by Aspergillus spp. The toxic effects of aflatoxins have adverse consequences for human health and agricultural economics. The aflR gene, a regulatory gene for aflatoxin biosynthesis, encodes a protein containing a zinc-finger DNA-binding motif. AFLR-Protein three-dimensional model was generated using Robetta server. The modeled AFLR-Protein was further optimization and validation using Rampage. In the simulations, we monitored the backbone atoms and the C-α-helix of the modeled protein. The low RMSD and the simulation time indicate that, as expected, the 3D structural model of AFLR-protein represents a stable folding conformation. This study paves the way for generating computer molecular models for proteins whose crystal structures are not available and which would aid in detailed molecular mechanism of inhibition of aflatoxin.     

Hormonal function of the hypophyseal-adrenocortical system in the pathogenetic heterogeneity of post-stress depressions

Original behavioral strategy is an important prerequisite for the pathogenesis of post-stress psychopathologies. Heterogeneity of these pathologies depends on the functional activity of hypophyseal-adrenocortical system.     

Psychomotor responsiveness to corticoliberin in rats with active and passive adaptive strategy in water-immersion paradigm of depression

A single intranasal injection of CRH alters adaptive behavior only in active rats. In particular this procedure results in increase of their behavioral passivity and reduction of psychomotor responsiveness. This neurohormone causes the same effect in active rats being injected by means of the same routine 20 days after animals have been exposed to a single water-immersion stress. But this effect of CHR is not observed after injection of the neurohormone to depressed animals in the stress-restress paradigm. Passive rats, intact or depressed, do not show any behavioral changes, while active ones develop signs of depression after repeated CRH intranasal injection.