Biochemical mechanisms in the phosphatidylinositol effect.
Stimulated labeling of phospholipids from 32Pi is a hallmark of activation of a variety of cell surface receptors. In the case of the central nervous system, the response can reflect muscarinic activation. Recent studies in nerve ending preparations indicate a postsynaptic site of action. Ca2+ is required for the expression of cholinergic stimulation of labeling in nerve ending preparations, but whether it plays a regulatory role is not yet known. While it is inferred that the receptor-ligand interaction leads to increased diacylglycerol availability, its source is not established. In experiments with muscarinic agents and ionophore added to nerve ending preparations, there is a potentiated loss of labeling from prelabeled polyphosphoinositides. It is suggested that phosphodiesteratic cleavage of polyphosphoinositides may be an early consequence of muscarinic receptor activation.
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D008563:Membrane Lipids / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D013570:Synaptic Membranes / Q000378:metabolism; D013574:Synaptosomes / Q000378:metabolism
D008563:Membrane Lipids; D010716:Phosphatidylinositols; D010761:Phosphorus Radioisotopes