Incorporation of [32P]orthophosphate into brain-slice phospholipids and their precursors. Effects of electrical stimulation.
1. The incorporation of [(32)P]phosphate into phospholipids was measured in slices cut from the pial surface of guinea-pig cerebral cortex; incorporation into the phosphorus of some water-soluble precursors of phospholipid was measured under similar conditions. 2. Slices subjected to overall electrical stimulation at a frequency of 5pulses/sec. differed from control slices in their pattern of phospholipid labelling. After 1hr. of stimulation, incorporation of [(32)P]phosphate into phosphatidylcholine, ethanolamine phospholipid and cardiolipin was respectively 54, 55 and 58% of the control value, and that into phosphatidylinositol was 186% of control. Phosphatidic acid labelling tended to increase with electrical stimulation, but the statistical significance of this change was marginal. Labelling of phosphatidylglycerol and di- and tri-phosphoinositides was not affected significantly by electrical stimulation. 3. Electrical stimulation of the tissue altered the specific radioactivities of water-soluble precursors of phospholipid. 4. The turnover rates of the phosphate groups of phospholipids were estimated approximately from the specific radioactivities of phospholipids and their precursors. Phosphatidylinositol (and its lipid-soluble precursors) showed the largest change in turnover rate in response to electrical stimulation of the tissue; the turnover rates of other lipids were also affected. Changes in the specific radioactivity of phospholipids did not correspond to changes in turnover in these experiments.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D004558:Electric Stimulation; D006168:Guinea Pigs; D066298:In Vitro Techniques; D010710:Phosphates / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000096:biosynthesis; D010714:Phosphatidylethanolamines / Q000096:biosynthesis; D010716:Phosphatidylinositols / Q000096:biosynthesis; D010743:Phospholipids / Q000096:biosynthesis*; D010759:Phosphorus Isotopes
D010710:Phosphates; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010716:Phosphatidylinositols; D010743:Phospholipids; D010759:Phosphorus Isotopes