Interaction Between Allopregnanolone and Amiloride Binding Sites on the GABA Receptor.

Allopregnanolone (Allo) is a positive allosteric modulator of the GABA receptor, and amiloride (Ami) is a competitive antagonist of the GABA receptor. The purpose of this work was to study the combined effect of Allo and Ami on functional activity of GABA receptor. The GABA-induced chloride current (I) was measured in isolated Purkinje cells of rat cerebellum using the patch-clamp technique and a system of fast application.

Corticosteroids as Selective and Effective Modulators of Glycine Receptors.

The mechanism of the negative impact of corticosteroids on the induction and progress of mental illness remains unclear. In this work, we studied the effects of corticosteroids on the activity of neuronal glycine receptors (GlyR) and GABA-A receptors (GABAR) by measuring the chloride current induced by the application of GABA (2 or 5 μM) to isolated cerebellar Purkinje cells () and by the application of glycine (100 μM) to pyramidal neurons of the rat hippocampus (). It was found that corticosterone, 5α-dihydrodeoxycorticosterone, allotetrahydrocorticosterone, cortisol, and 17α,21-dihydroxypregnenolone were able to accelerate the desensitization of the at physiological concentrations (IC values varying from 0.

Effect of nootropic dipeptide noopept on CA1 pyramidal neurons involves α7AChRs on interneurons in hippocampal slices from rat.

Noopept (NP) is a proline-containing dipeptide with nootropic and neuroprotective properties. We have previously shown that NP significantly increased the frequency of spontaneous IPSCs in hippocampal CA1 pyramidal cells mediated by the activation of inhibitory interneurons in stratum radiatum. The cholinergic system plays an important role in the performance of cognitive functions, furthermore multiple behavioral and clinical facts link NP with the cholinergic system.

Positive allosteric modulators of GABA receptor restore chloride current from blockade by competitive antagonists in a ligand-dependent manner.

γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter. GABA receptor type A (GABAR) possesses binding sites for a large group of pharmacological agents which are supposed to interact allosterically with each other. The aim of this work was to study the interaction between the positive allosteric modulators (PAMs) and the competitive antagonists of GABARs.

Synthesis of Glycyrrhizic Acid Conjugates with S-Benzyl-L-Cysteine and Their Antiviral Activity.

A new method for the synthesis of glycyrrhizic acid (GA) conjugates with S-benzyl--cysteine using 1-ethyl-3-(3-dimethylaminoproopyl)carbodiimide is proposed. It is established that 3--{2--[-(β--glucopyranosyluronyl)--cysteine--benzyl]--(β--glucopyranosyluronyl)--cysteine--benzyl}-(3β,20β)-11-oxo-30-(-carbonyl--cysteine--benzyl)-30-norolean-12-ene is superior to GA in inhibiting the accumulation of HIV-I virus-specific protein p24 (viral antigen) in MT-4 cell culture (IC 3 μg/mL, SI 90) and is 50 - 55 times less toxic to cells than azidothymidine.