[Effects of the platelet activating factor on the proliferation and IgE secretion by U-266BL human myeloma cells].

Platelet activating factor (PAF) influences the proliferation and IgE secretion by U-266BL human myeloma (HM) cells. At a relatively high PAF concentration (up to 10(-8) M), the rate of proliferation is significantly decreased, while the IgE secretion rate is increased. At low PAF concentrations (10(-11) M), the HM cell proliferation rate increases, whereas their ability to IgE secretion decreases.

[Effect of 1,2,3,4-tetrahydroimidazo[4,5-c]pyridine and 1,2,3,4-tetrahydroisoquinoline derivatives on the behavior and the brain receptor system in rats].

Adducts obtained via the interaction of formaldehyde with histidine (1,2,3,4-tetrahydroimidazo[4, 5-c]pyridine-3-carboxylic acid (I)), tyrosine (7-hydroxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (II)), and dopamine (6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (III)) influence the behavior and the state of the brain receptor system of rats upon chronic administration (10-day treatment at a daily dose of 50 mg/kg, i.p.).

[The action of korazol on the defensive behavior of rats].

The paper shows the dependence of behavioral changes provoked by corazol on individual characteristics of the animals. The rats with high activity in the ATS demonstrated the highest response to the drugs.

[Changes in the emotionally conditioned behavior of rats under the influence of the hexapeptide fragment GLLDLK of the protein inhibitor of diazepam binding].

It is shown that suboccipital injection of 100 micrograms of the gexapeptide GLLDLK (the fragment of endogenous peptide--the inhibitor of diazepam binding) modified (for 1-3 days) the emotionally conditioned behaviour of the rats (the test of "emotional resonance"). This modification was realized in some reinforcement of different behavioural patterns and had signs of anxiety and depression. In the test "social hierarchy" the injection of GLLDLK didn't change significantly the hierarchy in the whole rat society, but in the recipient behaviour the exploratory activity has been changed, the time of grooming increased and the quantity of social contacts decreased.

[Effect of nucleotides on N-methylcytisine and dimethyltubocurarine binding by the nicotinic acetylcholine receptors of the optic ganglia in the squid B. magister].

The effect of nucleosides mono-, di-, and triphosphates on binding of 3H-N-methylcytisine and 14C-tubocurarine to nAChR from squid optical ganglia were investigated. It was found, that ATP and GTP potentiate the specific binding of 3H-N-methylcytisine and inhibit the one of 14C-tubocurarine. While conducting the photoaffinity modification of nACHR by 3H-azidomethylcytisine in the presence of ATP the increase of specific incorporation of label was observed in comparison with control.

[Effect of amino acid derivatives of beta-carboline-3-carboxylate on rat behavior].

It was shown, that administration of methyl ether N-(beta-carboline-3-carbonyl)-glycine (GA) at dose level of 1-10 mg/kg markedly reduced exploratory behavior and motor activity in the open field test and facilitated manifestation of different rats defend reaction types. Methyl ether N-(beta-carboline-3-carbonyl)-leucine (LA) at the same doses was less effective. Besides GA (10 mg/kg) like earlier described anxiogenic compound FG 7142 suppressed isolation induced muricide behavior of rats.

[Effect of amino acid derivatives of beta-carboline on the evoked activity of hippocampal neurons].

The action of methylamide-beta-carboline-3-carboxylate (1), glycinamide-beta-carboline-3-carboxylate methyl ester (2), leucinamide-beta-carboline-3-carboxylate methyl ester (3) on evoked activity of hippocampal neurons was investigated using brain slice technique. Both 1 and 2 application (5 mkM, 15 min) reduced paired-pulse inhibition (PPI). Single-pulse and frequency stimulation revealed population spike (PS) increase or generation of additional PS after 1 or 2 application, the former drug being more active at all stimulation patterns.

[N-methylcytisine--a selective ligand of nicotinic receptors of acetylcholine in the CNS].

The ability of cytisine and its N-methyl derivatives to bind to nicotinic acetylcholine receptors (nAChR) from different tissues was studied. Cytisine and N-methylcytisine have high affinity (KD = 50 nM) to nAChR from squid optical ganglia. N,N-dimethylcytisine did not show high affinity to this receptor.

[Comparative study of the effect of 3-carboxy-beta-carboline methylamide and diazepam on rat behavior].

The effects of benzodiazepine receptor agonist, diazepam, and inverse agonist, FG 7142, were examined. Strong antagonism between FG 7142 (10 mg/kg) and diazepam (1 mg/kg) activity was revealed in the open field test. On the other hand, both FG 7142 and diazepam inhibited isolation-induced intraspecies aggressive behaviour of rats.

[Structural characteristics of the recognition site of cholinergic ligands of the nicotinic acetylcholine receptor from squid optic ganglia].

The effect of chemical modification on the binding of cholinergic ligands to nicotinic acetylcholine receptor from squid optical ganglion was studied. The existence of two chemically distinct subpopulations of binding sites was postulated. Subpopulation I contains, in all probability, Arg, Tyr and carboxyl groups critical for the binding of both ligands.

[Comparative study of the muscarinic cholinoreceptors of the glial cells in the human and rat cerebral cortex].

Radioligand analysis was used to study and compare muscarinic cholino receptors from human and rat brain glial cells containing no neurospecific proteins. It was demonstrated that 3H-quinuclidinyl benzylate has a higher affinity for muscarinic cholino receptors of human glia (Kd 2.0 nM) than receptors of rat glial cells (Kd 9.

[Pharmacological characteristics of the acetylcholine and L-glutamate receptors of the subpharyngeal ganglion neuron in the mollusk Zachrysia guanensis].

The presence of acetylcholine and L-glutamate receptors sensitive to the cholinoreceptor-specific ligands cytizine and tubocurarine has been demonstrated by means of microapplication of acetylcholine and L-glutamate to the central parietal zone of the subpharyngeal ganglion of the mollusc Zachrysia guanensis. Azidocytizine inhibited the function of acetylcholine receptor but did not affect glutamate receptor. Based on the electrophysiological data and analysis of ligand conformations a model has been designed for a site where L-glutamine is recognized by glutamine receptor.

[Action of beta-carboline derivatives on the evoked activity of hippocampal neurons].

The effects of tetrahydro-beta-carboline-3-carbonic acid methyl ester (I), 1-phenyl-tetrahydro-beta-carboline-3-carbonic acid methyl ester (II), tetrahydro-beta-carboline-3-carbonic acid methylamide, and beta-carboline-3-carbonic acid methylamide on evoked potentials (EP) of neurons were investigated in experiments with hippocampal slices. Each compound was tested in 5 experiments. These derivatives applied in a concentration 4 M had the following features in common: 1) a 10-20% augmentation of the amplitude of the population spike (PS) evoked in the CAI area by Schaffer collaterals stimulation; 2) appearance of additional PSs; 3) potentiation of the substance effect after beginning of washing; 4) poor washing (incomplete recovery of EP after 40-60 min of washing).

[Probable mechanism of recognition of cholinergic ligands by acetylcholine receptors].

Dryding's models were used for the conformational analysis of compounds affecting muscarin-specific acetylcholine receptor and nicotin-specific acetylcholine receptor. Ammonium group and ether oxygen (3.6 A apart from the ammonium group) specifically oriented to each other were shown to be necessary structural elements to reveal muscarin-type cholinergic activity.