[Age-related peculiarities of the hypothalamo-hypophyseo-adrenal system in chronic heterotypic stress].

Age-related peculiarities of the adaptation of the hypothalamo-hypophyseo-adrenal system (HHAS) to the effect of heterotypic stress was studied experimentally in the context of stress-associated behavioral reactions. Young (3 month old), mature (6 month old) and aging (12 month old) Sprague Dawley rats (total number of animals equal to 36) were exposed to chronic heterotypic stressors for 7 days with the subsequent testing of their behavioral responses. Histological changes were studied in the hypothalamus, pituitary and adrenal glands as compared to age-matched control; immunohistochemical reactions were performed to demonstrate CRF, ACTH, ED1, PCNA and caspase-3 with subsequent image analysis. In the aging organism, as compared to young and mature animals, the degree of HHAS activation indicated the dissociation in its central part and adaptive desensitization prevention, typical to young and mature animals. Specifically, in the aging animals exposed to stress, high hypothalamic CRF expression was noted in association with relatively low hypophyseal ACTH expression and high level of adrenal activity. Reduced HHAS plasticity in the aging animals as compared to that in the other age groups, corresponded to their behavioral changes, demonstrating the reduced capacity of the aging organism to adapt to the exposure of unpredictably changing stressors.

[Age-related changes of the pituitary folliculo-stellate cells in rats in chronic stress].

UNLABELLED: Folliculo-stellate cells are known as S-100 protein immunopositive cells of the anterior lobe of pituitary gland which are not secreting hormones and are presumed to be organ specific stem cells of the adenohypophys. Their role in adaptation of the body to stress remains unclear. AIM: To evaluate dynamics of folliculo-stellate and hormone-producing cells in rats of different age in chronic stress exposure. MATERIALS AND METHODS: Sprague-Dawley rats aged 1, 3, 6 and 12 months were exposed to chronic immersion immobilization stress. Histological section of the pituitary glands were stained immunohistochemically with subsequent image analysis. RESULTS: In control rats S-100 protein-immunopositive cells increased in number with age and negatively correlated with the number of ACTH-positive cells. In experimental animals aged 1 and 3 months volume density of S-100 protein-immunoreactive cells significantly decreased and negatively correlated with ACTH-positive cells, while in 6 month old rats it was only slightly decreased and in 12 months old animals showed tendency to increase. CONCLUSIONS: Results of the study demonstrating capacity of the folliculo-stellate cells to contribute to the plasticity of the hypothalamo-hypophyseo-adrenal axis in chronic stress exposure at different age.

Immunohistochemical characteristics of the hypophysis in normal conditions and chronic stress.

Quantitative immunohistochemical methods were used to assess activation of the hypothalamo-hypophyseal-adrenocortical system at the level of its central component - the adenohypophysis - in the growing body during chronic exposure to psychoemotional stressors of different strengths. Sprague-Dawley rats aged 30 days were subjected to "mild" or "severe" immobilization stress for 5 h per day for seven days. Animals were decapitated at the end of the last stress session and the endocrine glands (hypophysis, adrenals) were harvested, weighed, and embedded in paraffin; sections were stained with hematoxylin and eosin, and also immunohistochemically using monoclonal antibodies to adrenocorticotropic hormone (ACTH) and proliferating cell nuclear antigen (PCNA) following by automated image analysis. These studies showed that stress-associated hyperplasia of corticotropocytes in rats of pubertal age was due more to the differentiation of existing immature precursor cells than to cell proliferation.

[Immunohistochemical characteristics of the spleen under the effect of various types of stressors].

The effect of different types of stressors (physical and psychoemotional) on the splenic immunoarchitecture in prepubertal Sprague-Dawley rats was evaluated using the quantitative immunohistochemical methods. Rats aged 1 month were exposed to chronic stress for 5 hours daily during 7 consecutive days. After the last stress session, animals were sacrificed, spleen was obtained for weighing and processed for routine histology and immunohistochemistry (CD3, CD8, CD90, CD20, ED1, PCNA, caspase-3) with subsequent computer image analysis. The results obtained demonstrated that the range of stress-induced immunosuppressive changes in the splenic compartments was associated with the type of stressor. Chronic exposure to purely psychological stress resulted in the decreased volume of the splenic white pulp associated mainly with the reduction of T-cell subcompartments with the decrease in their cellularity and the reduction of volume density of CD90+ and CD8+ cells in them compared to those in age-matched control animals, while the physical stressor affected both T- and B-subcompartments of the white pulp causing the reduction of lymphoid nodule volume, marginal zone width and volume density of CD20+ cells. Hypoplasia of the splenic B-zones was mainly associated with increased splenocyte apoptotic rate while that of the T-zones--with decreased proliferation rate and attenuated traffic of the recent thymic immigrants into the spleen.

[Antioxidative defense parameters in acute and chronic cholecystitis].

A hundred and fifty-two patients cholelithiasis were examined. Among them, 69 and 83 patients were operated on for acute destructive and chronic cholecystitis, respectively. In destructive cholecystitis, there is a high lipid oxidation rate accompanied by the elevated levels of nonenzymatic antioxidant ceruloplasmin. The low activity of catalase and ceruloplasmin and the decreased content of ascorbic acid suggest the depletion of antioxidative defense in patients with cholelithiasis with significant liver disease. The magnitude of changes in the activity of antioxidative enzymes and the level of the nonenzymatic antioxidant ascorbic acid depend on the state of the liver.

[Immunohistochemical characteristics of the hypophysis under normal and stress-associated conditions].

Quantitative immunohistochemical investigation was undertaken to detect the peculiarities of the activation of the hypothalamic-hypophyseal-adrenocortical system at the level of its central unit--the adenohypophysis--in the growing organism under the conditions of chronic exposure to psycho-emotional stressors of varying intensities. Sprague-Dawley rats aged 30 days were exposed to either mild or severe chronic restraint stress for 5 hours during seven consecutive days. After the last exposure to stress, rats were decapitated, the endocrine glands (pituitary and adrenal glands) were removed, weighted, and embedded in paraffin; histological sections were stained with hematoxylin and eosin. Sections of hypophysis were also stained immunohistochemically using the monoclonal antibodies against adrenocorticotropic hormone (ACTH) and proliferating cell nuclear antigen (PCNA) with subsequent image analysis. The results of the study suggest that the stress-related hyperplasia of corticotropocytes in the hypophyseal pars distalis of the peripuberal rats was mainly associated with differentiation of the immature precursor cells of the hypophysis rather than with the increased cell proliferation.

[Antioxidants in the treatment of cholelithiasis patients]. / Antioksidanty v lechenii bol'nykh kholelitiazom.

Results of examination and treatment of 157 patients with cholelithiasis against the background of a liver pathology were summed up. The antioxidant system in such patients was studied. The degree of a decrease of catalase activity in the liver and blood serum as well as the ascorbic acid content were found to depend on the liver state of patients with cholelithiasis. Greatest changes were found in patients with cirrhosis of the liver and chronic active hepatitis. The method of complex treatment of cholelithiasis patients with non-enzymatic antioxidants alpha-tocopherol and ascorbic acid is proposed. Activity of organ specific liver enzymes urokaninase and histidase was used for the estimation of treatment efficiency. Complex administration of ascorbic acid and alpha-tocopherol was shown to improve the liver function in patients operated upon for cholelithiasis.