[Effect of pineal peptides on the adrenal gland cortex glucocorticoid function and behavior in rats orally immunized with ovalbumin].

The influence of intraperitoneal injections of pineal peptides (5 mg/100 g of body mass during first five days of three weeks' oral immunization by ovalbumin) on the rats' behavior in the "open field" tests and on the blood corticosterone level, was investigated. It was found out that rats' oral immunization resulted in increasing of secretion activity of Peyer's patches antibody-producing cells, in decreasing of blood leukocyte cytokine-producing activity, in depression of the searching behavior and locomotor activity and in a significant (p < 0.05) lowering of the blood corticosterone level after 15 minutes in the "open field" tests. The pineal peptide injections caused an intensification of humoral immune response, a more obvious suppression of locomotor activity and searching behavior, and a significant decrease of the corticosterone level compared to the animals intraperitoneally injected by physiological solution. These data indicate that immuno-stimulative effect of pineal peptides combines with their ability to decrease glucocorticoid hormone secretion during stress-reaction.