J. D. Chanley

SOME PHARMACOLOGIC PROPERTIES OF HOLOTHURIN A, A GLYCOSIDIC MIXTURE FROM THE SEA CUCURMBER

Interest in the toxic principle holothurin, derived from the sea cucumber dctinopyga agassizi Selenka, stems largely from recent observations (Nigrelli, 1952; Nigrelli and Zahl, 1952; Nigrelli et al., 1955; Chanley et al., 1955) employing partially purified preparations that pointed to an antitumorous activity as well as a spectrum of other pharmacological actions. Among the latter, sufficient evidence of action against nerves was found to warrant the present study of the crystalline material on the propagated action potential in desheathed bullfrog sciatic nerve, on single nerve-fiber preparations from the frog, and on the rat nerve-diaphragm preparation.

Radioactive tracer studies of monolayers: II. Comparison of floating and built-up monolayers☆

Abstract The composition of built-up calcium stearate stearic acid layers has been studied with Ca45. The results diverge from those obtained by conventional chemical analysis of the floating layers (“H-layers”), from which the built-up layers were formed. Similar discrepancies have been observed when building layers of fatty acids on a hypophase containing bivalent organic cations. In all these instances the cations seem to form an integral part of the H-film, but are eliminated, probably by exchange against protons, during the building-up operation.