The role of nitric oxide in regulation of leukocyte migration into the heart tissue in vitro.

Characteristics of leukocyte migration have been studied during the incubation of the right and left ventricles of rat heart explants in autologous blood plasma. Within the first 60 min, the leukocyte amount in the medium increases. Moreover, it is associated with cell release from the heart tissue. During further incubation, the cell release decreases; after 3 h of incubation, the cells begin to migrate back into the heart tissue. However, neutrophil migration does not change. Sodium nitrite, being a donor of nitric oxide significantly, reduces the leukocyte migration from the heart explants into the incubation medium, especially from left ventricle explants.

[Dynamics of parameters of energy metabolism at adaptation to diving in human].

Studies of the diving reaction in the comparative-evolutionary aspect have shown that a complex of reactions providing the oxygen-saving effect during diving is inherent in human like in the secondary-aquatic mammals. This is confirmed by results of study of peculiarities of energy metabolism during imitation of diving (hold-up of respiration with immersion of face into the cold water--the cold-hypoxic-hypercapnic action) (CHHA). Data of gas analysis have shown that during the diving imitation the oxygen consumption rate is statistically significantly lower than during the usual hold-up of respiration (Genche's test). As shown by the study, this is due to the greater degree to vasoconstriction of peripheral vessels and selective redistribution of blood flow than to slowing down of the blood flow caused by reflex bradycardia during diving. It has been revealed that under effect of adaptation to CHHA, on the background of a decrease of the total energy consumption by the organism there occurs some increase of contribution of aerobic processes to its energy provision. Adaptation to CHHA has been shown to be accompanied by a decrease of reactivity of the parasympathetic chain of regulation of the heart chronotropic function and by an increase of duration of apnea. The duration of apnea is directly correlated with level of insulin--the hormone stimulating the anaerobic pathway of energy provision. Under effect of adaptation to CHHA there has been established an increase of the organism resistance to stress actions, which is confirmed by the lower levels of cortisol and thyroid hormones in representatives of the experimental group as compared with the control one.

[Comparative-physiological study of leukocyte participation in initiation of lipid peroxidation during nitrite intoxication in rats and muskrats].

The study is carried out on Wistar white rats non-adapted to oxygen deficit and on semiaquatic rodents muskrats adapted to periodic arrest of respiration during diving under conditions of Nembutal narcosis. It has been revealed that 1 h after a subcutaneous injection of sodium nitrite (3 mg/100 g body mass), intensification of lipid peroxidation (LPO) in the muskrat brain is absent, the activity of the antioxidant enzyme catalase increasing 16 times (p < 0/01) as compared with control injected with equivalent saline volume. In heart and liver, a statistically significant decrease of the content of LPO products active in the test with 2-thionarbituric acid; in the femoral muscle tissue, the LPO intensity does not change. In rats, unlike muskrats, after injection of sodium nitrite, an increase of LPO is recorded in brain, while a decrease of the LPO product content in the femoral muscle; in liver the LPO intensity did not change. In muskrats, the sodium nitrite administration leads to a decrease of the leukocyte spontaneous mobility, of lymphocyte cytokine-producing activity, and ofneutrophil bactericidal activity (by the content of cationic proteins in neutrophilic phagocytes), whereas in rats the leukocyte mobility does not change, only the blood neutrophil bactericidal activity decreases. The ability of neutrophils to produce the superoxide anion during the nitrite intoxication does not change both in rats and in muskrats. The obtained data allow concluding that under conditions of Nembutal narcosis the leukocyte functional activity on the background of nitrite intoxication is suppressed to the greater degree in the muskrats genotypically adapted to oxygen deficit than in immunocompetent cell of the rodents not adapted to hypoxia.

[Functional activity of the rat blood leucocytes during dynamics of nitric hypoxia].

Alert Wistar rats were subcutaneously injected with sodium nitrite (3 mg/100 g body weight), the control group rats were injected with saline. The blood was taken in 30, 60 and 90 minutes after the injection. Total leucocyte quantity and their subpopulations, the oxygen-dependent and oxygen-independent phagocytosis by neutrophils, functional activity of T-lymphocytes and their responsiveness to neurotransmitters and sodium nitrite and sodium nitrite and basal cell activity mobility were studied. It was shown that a more obvious alteration of the lymphocyte number, an increase of migratory and cytokine-productive activity, as well as augmentation of the cell sensitivity response to sodium nitrite and acetylcholine occurred in 30 minutes after the nitric oxide donor injection. At the same time, the neutrophil radical-productive activity and quantity of cationic peptides in neutrophils remained unchanged during nitric intoxication. At a later time, the leucocyte state did not change as compared with the control parameters.

[Pineal peptides in the regulation of milk-ejection reflex in lactating rats]. / Peptidy épifiza v reguliatsii refleksa vyvedeniia moloka u laktiruiushchikh krys.

The effects of pineal peptides (mol. mass 1-4 kDa) intranasal infusions on some parameters of milk-ejection reflex were investigated. Peptides were extracted from dairy-cattle pineal glands. Pineal peptides increase body weight, levels of water intake, plasma prolactin concentration and milk yield in rats when infusing daily in dose 1 microgram/kg from the third day of lactation. On 9th and 12th days of lactation during 1-hour nursing seance the significantly greater number of reflective milk ejections were found. When 1 hour before the peptides infusion rats were intraperitoneally injected by rabbit antiserum to oxytocin (200 microliters at dilution of 1:20) the effects of pineal peptides were significantly less expressive or were absent at all. Using enzymimmunoassay it was demonstrated that there were greater increasing of oxytocin content in pineal gland in suckling-induced oxytocin release from neurohypophysial system in the chronic pineal peptides-treated female rats compared with control. This effect was absent when rats were injected by oxytocin antibodies. These data suggest that pineal peptides can participate in forming of reflect oxytocin release pattern. This pattern is initiated by suckling and is limited by oxytocin content in blood.

[Mechanisms of human adaptation to hypoxia]. / O mekhanizmakh adaptatsii cheloveka k gipoksicheskomu vozdeistviiu.

The effects of adaptation to cold-and-hypoxic exposure on the cardiovascular system, lipid peroxidation and concentrations of adaptogenesis involved hormones were studied in male students. The two weeks cold- and hypoxic training was shown to be accompanied by a significant increase of apnea duration, reduced velocity of bradycardia development and a more rapid ECG post-cold and- hypoxic exposure normalization, as well as by inhibition of activation of adrenal cortex and thyroid gland after stress of different nature. The changes of the character of influences between the indices under study, were demonstrated. The correlation analysis showed an increase of the human's adaptive potential and a decrease of its dependence on the adrenal cortex hormones.

[Effect of pineal peptides on the adrenal gland cortex glucocorticoid function and behavior in rats orally immunized with ovalbumin]. / Vliianie peptidov épifiza na gliukokortikoidnuiu funktsiiu kory nadpochechnikov i povedenie oral'no immunizirovannykh oval'buminom krys.

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.

The effects of epiphyseal peptides on the release of immunoglobulins in Peyer's patches in rats in vitro.

The effects of epiphyseal peptides (1 microg/ml) on the release of immunoglobulins into the incubation medium by isolated Peyer's patches from non-immunized mice and mice immunized orally against ovalbumin were studied during 40-min incubations. The possibility that epiphyseal peptides act on adrenoreceptors of cells in secondary lymphoid organs in the small intestine was assessed using alpha- and beta-adrenoreceptor blockers, i.e., phentolamine HCl (0.02 mg/ml) and anaprilin (0.06 mg/ml) respectively. Basal levels of secretory activity in control Peyer's patches from immunized rats were 2.4 times (p < 0.01) greater than for the lymphoid organs of non-immunized animals. The effects of epiphyseal peptides on the secretory activity of antibody-forming cells depended on the functional state of Peyer's patches. Application of epiphyseal peptides led to a 35% increase (p < 0.05) in the release of immunoglobulins from Peyer's patches in non-immunized rats and a 25% decrease (p < 0.05) in the release of antibody into the incubation medium from the lymphoid organs of immunized animals. These data lead to the suggestion that the activatory effect of epiphyseal peptides on antibody-forming cells in Peyer's patches from non-immunized animals is associated with alpha-adrenoceptors, while their inhibitory action on immunoglobulin release by the small intestine lymphoid organs from immunized animals is not mediated via adrenoceptors.

[The influence of pineal peptides on in vitro immunoglobulin secretion by Peyer's patches in rats]. / Vliianie peptidov épifiza na vydelenie immunoglobulinov peierovymi bliashkami krys in vitro.

The influence of the pineal peptides (1 mcg/ml) on immunoglobulin secretion by rat's Peyer's patches isolated from nonimmunized rats and from orally immunized by ovalbumin during 40 min incubation, was investigated. Using alpha- and beta-adrenoblockers--phentolamine hydrochloride (0.02 mg/ml) and anaprilin (0.6 mg/ml), respectively--the possibility of pineal peptides' effect on the gut secondary lymphoid organ' adrenoreceptors, was evaluated. Basic levels of immunized rats' control Peyer's patches secretory activity were 2.4--fold (p < 0.01) higher than those of non-immunized rats. The effect of pineal peptides on antibody-producing cells' secretory activity depended on Peyer's patches' functional condition. Application of pineal peptides led to a 35% (p < 0.05) increasing of immunoglobulin secretion by non-immunized rat Peyer's patches and to a 25% (p < 0.05) decreasing of antibody production by immunized rats lymphoid organs. These data suggest that the pineal peptides activation influence on Peyer's patches antibody-producing cells of nonimmunized rats connected with alpha-adrenoreceptors, and inhibiting action of these peptides on immunized rats lymphoid organs immunoglobulin secretion are not mediated through adrenoreceptors.

[Activation of the antioxidant system as a factor in increasing the body resistance during combined adaptation]. / Aktivatsiia antioksidantnoi sistemy kak faktor povysheniia rezistentnosti organizma pri kombinirovannoi adaptatsii.

In semi-aquatic mammals (minks and muskrats) significant changes were found to occur in the leukocyte formula during adaptation to hypoxia, as compared with non-adapted rats and mice, although no increase in lipid peroxidation was found in any of their organs. This latter finding seems to be due to simultaneously enhanced activities of superoxide dismutase and catalase. In humans under professional stress, treatment with combined technology of adaptation: cold-and-hypoxic exposure, yields a positive therapeutic result accompanied by a decrease in lipid peroxidation and increase in superoxide dismutase and catalase activities in the blood. The data obtained suggest that the strategy of formation of protection against hypoxia and toxic free radical oxidation is common for the animals and humans.

[Pinealocyte functioning in stress during daytime in rats]. / Osobennosti funktsionirovaniia pinealotsitov u krys pri stresse v svetloe vremia sutok.

Several types of unit activity were detected in the rat pineal gland during a 48-hour water and food deprivation. The unit activity rate in stress was higher by 4-6 times than in intact rats (due to an increase in the "fast" cells number and switching of some cells from regular to a burst type of activity). Electrical stimulation of olfactory epithelium decreased the unit activity rate in the most active pinealocytes. The daytime increase in the pineal electrical activity reflects an intensification of secretion of the protein/peptide substances and, probably, serotonin but not the melatonin. Blocking exocytosis with colchicin revealed a close relation of the pinealocytes secretion with their electrical activity. Existence of central (olfactory in particular) mechanisms limiting the pineal activation, was shown.