[Characteristics of ultrastructure of the myocardium of rats with different resistance to oxygen deficiency after acute and periodic effects of hypoxia].

In experiments on rats with different resistance to oxygen deficiency (high-resistant--HR, and low-resistant LR animals) the myocardium ultrastructure of nonadapted and adapted rats was studied. It was shown that there were more glycogen granules and lipid drops initially in cardiomyocytes of nonadapted HR animals in comparison with LR ones. After a long-term adaptation to hypoxia the hypertrophia and hyperplasia of mitochondria, the nucleus and endoplasmatic reticulum hypertrophy were observed.

[The function of the peripheral adrenergic link under the action of neuroleptics in immobilization stress].

The morphofunctional state of different links of the sympathoadrenal system under the action of neuroleptics haloperidol and sulpiride was studied on the model of immobilization stress in rats. The drugs were shown to possess the effect of the pharmacological correction of hormone content in the adrenals and the level of the neuromediator activity of the adrenergic nerves at different stages of immobilization stress. The data obtained indicate the anti-stress action of the studied neuroleptics.

[Effect of the N-terminal fragment of substance P1-4 on the somatic manifestations of the stress reaction and on the catecholamine content of the adrenals in rats].

The antistress affect of the substance P1-4 N-terminal fragment (ARG-Pro-Lys-Pro, 100 mkg/kg, i.p.) has been studied on the model of immobilization stress in rats.

[Role of the peripheral catecholaminergic systems in the antistress action of neuropeptides].

The mediator activity of the peripheral catecholaminergic systems (the adrenergic nerves of dura mater and the concentrations of noradrenaline and adrenaline in the adrenals of rats) during dynamic and immobilization stress was investigated with the help of fluorescent microscopy and spectrofluorometry. Neuropeptides--dalargin and another enkephalin analog--were injected intraperitoneally, 150 mg/kg. A visible antistress action of these neuropeptides has been demonstrated, it was more marked after treatment with dalargin.

Effect of the N-terminal tetrapeptide of substance P SP (1-4) and tuftsin on the pre- and postsynaptic transmitter outflow in rat adrenal gland slices.

Two structurally related tetrapeptides, the N-terminal tetrapeptide of substance P SP(1-4) and tuftsin, exerted some similarities in modifying immune reactions and normalizing stress-induced disorders in the catecholamine system of adrenals. This paper presents results about the effects of tuftsin and SP(1-4) on the cholinergic-adrenergic interaction in rat adrenal gland slices. Both, tuftsin and SP(1-4) inhibited the nicotine-evoked [3H]noradrenaline outflow (postsynaptic effect), but the effect of SP(1-4) was more pronounced.