Effects of acetylcholine and other agents on 32P-prelabeled phosphoinositides and phosphatidate in crude synaptosomal preparations

✍ Scribed by H. L. White

• Book ID: 102908366
• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 690 KB
• Volume: 20
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490200117

✦ Synopsis

Experimental conditions are described which permit effects of various agents on polyphosphoinositides and phosphatidic acid (PA) to be evaluated simultaneously in crude nerve-ending preparations from rat brain. Acetylcholine (3-100 p M ) or carbachol(30-1,000 p M ) induced the hydrolysis of prelabeled polyphosphoinositides and, at the same time, stimulated the net label incorporated in phosphatidic acid. All muscarinic effects were blocked by atropine or pirenzepine. Nonmuscarinic agonists (glutamate, adenosine, norepinephrine) stimulated polyphosphoinositide hydrolysis in this preparation, but of these only norepinephrine affected phosphatidic acid turnover. A potentiation of acetylcholine-induced phosphoinositide turnover by KCI was observed, as well as an apparent selective inhibition of PIP2 hydrolysis by LiCI. Acetylcholinestimulated turnover of PA was not necessarily coupled to phosphoinositide hydrolysis.