Time course for labeling of brain membrane phosphoinositides and other phospholipids after intracerebral injection of [32P]-ATP. Evaluation by an improved HPTLC procedure.
An improved two-dimensional HPTLC procedure was developed for separating phospholipids including individual phosphoinositides, phosphatidic acids and plasmalogens. This procedure was used to examine the time course for uptake of label by phospholipids in brain subcellular membranes after intracerebral injection of [gamma-32P]-ATP. There were considerable differences in the phospholipid labeling pattern among different subcellular fractions. In particular, a high proportion of labeled phosphatidylinositol 4,5-bisphosphates and phosphatidic acids was found in the myelin fraction during the initial 4 hr after injection. In other subcellular fractions, labeling of phosphoinositides was maximum at 2 hr, but with prolonged time, poly-phosphoinositides started to show a decline in radioactivity whereas labeling of other phospholipids continued to show a steady increase instead. Results indicate at least two different modes for the uptake of label by brain membrane phospholipids after intracerebral injection of [32P]-ATP.
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Sinclair Comparative Medicine Research Farm, University of Missouri, Columbia 65203-9497.
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D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D007276:Injections, Intraventricular; D007425:Intracellular Membranes / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008861:Microsomes / Q000378:metabolism; D009186:Myelin Sheath / Q000378:metabolism; D010712:Phosphatidic Acids / Q000378:metabolism; D010716:Phosphatidylinositols / Q000302:isolation & purification / Q000378:metabolism*; D010743:Phospholipids / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000378:metabolism
D010712:Phosphatidic Acids; D010716:Phosphatidylinositols; D010743:Phospholipids; D000255:Adenosine Triphosphate