The Flocculation of Lecithin by the Extracts of Adrenal Glands.

Abstract

In a previous publication 1 I have described the following reaction: The lipid of adrenal glands is flocculated in an aqueous emulsion in the presence of living tissue, oxidized adrenalin and H₂O₂. After sedimentation of the floccules it is possible to determine the presence of cholin and phosphoric acid in the supernatant liquid. It was observed that this phenomenon occurs very quickly, especially at body temperature, that oxidized adrenalin is not necessary, and that H₂O₂ only increases the speed of this reaction but does not cause it. Instead of living tissue a native preparation of blood albumen was used, which was found to be necessary and sufficient.

In this way the reaction became very simple: A lipid emulsion of adrenals is flocculated in the presence of native blood albumen. Another lecithin (lecithin ex ovo Merck) did not show this reaction. A very important condition is the integrity of the albumen; if this is denaturated the reaction is negative. The optimal temperature is body temperature; lower temperature inhibits the reaction; a higher one causes a denaturation of the proteins, so that the flocculation does not appear. The albumen does not enter into the reaction with the lipids; neither is it destroyed. After the reaction and after filtration it is possible to denature the albumen or to use it for a new reaction. It acts probably as a catalyzer (ferment?).

It was always possible to determine after flocculation and filtration, a certain amount of cholin and phosphoric acid in the clear solution, which obviously originates from the decomposition of lecithin. But this decomposition is perhaps only an accompanying phenomenon; the main manifestation is the flocculation.