The enhanced biliary secretion of a taurine conjugate in the rat after intraduodenal administration of high doses of fenclozic acid.

1. The metabolic fate of [14C]fenclozic acid (ICI 54450) in rat was determined after intraduodenal administration at different doses. 2. Increasing the dose from 2 to 100 mg/kg resulted in a five-fold increase in drug-related material secreted in bile. 3. At a dose of 2 mg/kg the taurine conjugate was a relatively minor metabolite, whereas at 100 mg/kg this conjugate was the major metabolite in bile and urine. 4. Enhanced biliary secretion of the taurine conjugate in rats receiving multiple doses of fenclozic acid results in exposure of the intestinal cells to much greater concn. of drug-related metabolites.

Membrane-potential-sensitive dyes for optical monitoring of activity in Aplysia neurons.

Two membrane-associated dyes (WW375 and NK2367) which change their absorption of light when the membrane potential changes have been studied using several preparations form Aplysia. Action potentials are easily observed in nerve trunks (from a number of axons), in bag cell clusters, in some of the larger single cells of the parietovisceral ganglion, and in the optic nerve. Physiological effects of the dyes on the circadian rhythm of activity in the eye are described.

Distribution and behaviour of isoselenium salts in organism. III. Radioprotective effect of selenium derivatives.

Radioprotective properties of Se-2-aminoethylioselenouronium bromide hydrobromide, 2-aminoselenoazoline and of selenium analogue of mercaptoethylguanidine were followed. Radio-protective effectiveness comparable with classical thiol radioprotectiva was manifested by 2-aminoselenoazoline. In the other two compounds there was on the contrary found a synergism of toxicity and radiation.