Administration of streptozotocin caused selective damage to endocrine β-cells in rat pancreatic islets, which was related to activation of apoptosis. The cytotoxic effect of streptozotocin was associated not only with DMA damage due to dysfunction of the antioxidant defense system, but also with activation of the caspase cascade and TNF-related apoptosis-inducing ligand.

Serum concentration of L-carnitine, the mean thickness of the skeletal muscle fiber, and exercise performance in the forced swimming test decreased in rats receiving a carnitine-deficient diet. Treatment with L-carnitine compensated for carnitine deficiency, while racemate and D-stereoisomer did not increase its level. L-Carnitine, but not racemate and D-stereoisomer, promoted recovery of the skeletal muscle fiber thickness and exercise performance of rats.

Pronounced transformation of cells in mesenteric lymph nodes, mainly in the thymus-independent zone and sinuses, was detected in albino mice experimentally infected with West Nile fever (strain 986). Maximum antigen-presenting activity was exhibited by activated macrophages, minimum activity--by dendritic cells of lymphoid follicles.

The rats were divided into groups demonstrating extremely high and low stress reactivity depending on the results of testing for the nociceptive threshold and thermolability in response to bacterial lipopolysaccharide administration. Specific structural features of the nucleus and mitochondria were revealed in neurons of the hypothalamic suprachiasmatic nucleus in rats with constitutionally high reactivity, which reflects high functional activity and stress-induced lability of these structures. Ultramicroscopic study revealed phenotypic differences in one of the key hypothalamic nucleus, which enables potent and rapid neurogenic response of the stress system in animals with high stress reactivity.