[Effects of glycyrrhetic acid on transmitter secretion].

The investigation of the effects of glycyrrhetic acid on spontaneous secretion of transmitter from neurotermination of the frog neuromuscular synapses showed that this substance, unlike glycyrrhizic acid, increased the frequency and amplitude of m. e. p.

Arabidopsis assay for mutagenicity.

Four laboratories, two in the Czech Republic (Brno and Prague) and two in the CIS (Moscow and Duschanbe), participated in the International Programme on Chemical Safety's (IPCS) collaborative study to evaluate the utility of the most commonly used plant test systems, including the Arabidopsis thaliana assay, for assessing the mutagenic potential of environmental agents. Out of the five compounds evaluated in the Arabidopsis assay, three compounds, i.e.

The anticoagulant action of phospholipase A from Eresus niger spider venom.

Phospholipase A, named component EnPA, was isolated from Eresus niger spider venom. It was determined to be a single peptide chain with mol. wt of 13,000.

[Menadione induction of Ca2+ efflux from the mitochondria and of mediator secretion from the nerve endings].

It is shown that menadion increases the rate of Ca2+ efflux from mitochondria which decreases in the presence of ditiotreitol. Menadion at concentration of 50 microM induces Ca2+ efflux from mitochondria and its effect on synaptic transmission is discussed.

[Mechanism of action of endotoxins in chronic renal failure].

Altogether 76 patients with terminal chronic renal failure (CRF) were examined for the intensity of endogenous intoxication and its action mechanism in blood serum. To determine the degree of intoxication, use was made of neuromuscular preparations of Rana temporaria. In order to study the action mechanism of the toxic substances of uremic genesis, a study was made of the effect of CRF patients' blood serum on the conduction of bilayer lipid membranes.