The chromatographic separation of polyphosphoinositides and studies on their turnover in various tissues

Abstract

1. 1. 32P-labeled spots obtained when total lipid extracts from tissue slices are chromatographed on silicic acid-impregnated paper with phenol-ammonia as the developing solvent been characterized as di- and triphosphoinositide. This has enabled us to develop a simple, rapid, quantitative method for assaying the radioactivity incorporated into di- and triphosphoinositide in large numbers of small samples of tissue. 2. 2. Slices of salts gland, brain cortex, kidney, liver, pancreas, and heart ventricle incorporated 32P into di- and triphosphoinisitide when incubated in physiological saline containing [ 32P]orthophosphate. With the exception of liver, the incorporation into triphosphoinositide was higher. The incorporation into diphosphoinositide generally paralled that into triphosphoinositide. 3. 3. Under conditions in which 32P incorporation into phosphatidic acid and phosphatidyl inositol was stimulated by acitylcholine in salt-gland slices, there was an inhibition of incorporation into the polyphosphoinositides.