Quantification of human platelet inositides and the influence of ionic environment on their incorporation of orthophosphate-32P

Abstract

A C T Platelets are a rich source for the study of inositol lipids in man. The substitution of an EDTA-KCl solution for the water component of the Bligh and Dyer procedure permitted quantitative extraction of polyphosphoinositides. The latter, with monophospho- inositide, were found to comprise, on a molar basis, 6.7% of total platelet phospholipids. Study of the incorporation of orthophosphate-'P into platelet phospholipids was further simplified by separating eight 'P-labeled lipids, including the inositides, with a single chromatographic development on formaldehyde-treated paper. Particular attention was paid to the influence of ionic environment on the pattern and degree of labeling.