[The effect of dalargin on the opioid and immune systems in patients with a depressive syndrome].

Depressed patients and healthy donors received dalargin. As shown by the radioreceptor test, the patients recovered normal quantitative and qualitative values of plasma opioid activity due to this drug which is a synthetic agonist of sigma-type opioid receptors. Lymphocyte proliferative activity (spontaneous and induced by polyclonal mitogens) was not significantly different in the test subjects versus the donors, though in vitro studies revealed multidirectional homeostatic effects of dalargin.

[The normalizing effect of dalargin on the glucocorticoid and opioid levels of the blood in CBA and C57Bl/6 mice undergoing footshock stress].

Radioreceptor investigations showed that it is impossible to interpret changes in the activity of opioid receptor ligands of mu and delta types in plasma of mice under footshock stress (FSS) as activation or depletion of opioid system (OS). There occurred qualitative changes characterized by interstrain differences (ID). These are also typical for dynamics of development of FSS effects on blood corticosterone levels.

[The effect of different methods of isolating thrombocytes on the surface structure and biochemical parameters of the serotonin system of these cells].

The method of platelets' isolation influences their morphofunctional state. The study of the surface structure of platelets with the method of scanning electron microscopy shows, that the nonactivated form of platelets is characterized for the cells, isolated by gel filtration, but platelets which are isolated by centrifugation are activated. Platelets' activation under centrifugation is shown to connect with the changes of biochemical parameters of platelet serotonin system: the increase of the velocity of the 3H-serotonin reuptake and of the 3H-imipramine specific binding.

[A decrease in the content of immunoreactive alpha- and gamma-endorphins in the blood and the suppression of their hypersecretion under the influence of dexamethasone in emotional stress in monkeys].

Daily administration of 12 mg of dexamethasone to monkeys during 10 days resulted in decrease of the levels of alpha- and gamma-endorphins and cortisol 7 days after the first injection. The titers of these peptides in plasma of monkeys. exposed to two hours of immobilization stress were elevated twice above basal levels.

High- and low-affinity [3H]imipramine binding sites on human platelets: separate determination and involvement of sulphur-containing bonds.

We have confirmed the presence of two different classes of [3H]imipramine ([3H]IMI) binding sites on human platelets: high-affinity (Kd = 0.52 nM, Bmax = 1670 fmol/mg protein) and low-affinity (Kd = 101 nM, Bmax = 8,000 fmol/mg protein) binding sites. The high-affinity component of [3H]IMI binding can also be obtained separately as the difference between specific [3H]IMI binding in Na-containing and Li-containing incubation buffer.

[Effect ot thyroliberin on rat brain opiate receptors].

The ability of thyroliberin to interact with opiate receptors of the rat midbrain and hypothalamus has been studied. It was shown by competitive displacement analysis that thyroliberin did not replace labeled opioid peptides in opiate receptor binding sites when added in vitro at concentrations of up to 10(-5) M. The specific binding of opioid peptides was increased by 10-20% in the presence of 10(-7)-10(-6) M thyroliberin.

Thymus peptides interacting with opiate receptors.

The substances displacing labelled ligands from opiate receptors of the rat brain membrane fraction were found in the thymosin fraction 3 and acetoacid extract of the thymus by the radioreceptor assay. Comparison of the displacing activity of acetoacid extracts of perfused and non-perfused thymus and peripheral blood as well as an estimation of the blood content in the thymus allowed to conclude that blood does not participate in the ability of thymus preparations to bind to opiate receptors. On the basis of the enzymatic treatment data one can conclude that opiate receptor ligands present in thymus preparations are of peptide nature.