Biosynthesis of acyl-specific glycerophospholipids in mammalian tissues. Postulation of new pathways.

A review of the literature concerning the synthesis of acyl-specific glycerophospholipids indicates that the known biosynthetic sequences cannot satisfactorily explain these specific acylations . New de novo and salvage pathways are proposed to account for the acyl composition of highly unsaturated and saturated glycerophospholipids. In these hypothetical pathways, de novo synthesized glycerophosphodiesters are postulated to be key intermediates to establish the specific acyl composition of the resulting glycero-phospholipids, and to be integrated with the known cytidine pathways. A re-interpretation of the experimental literature in terms of these postulated pathways is provided, with some methods to test these proposed sequences.