EFFECT OF NOREPINEPHRINE ON 32P INCORPORATION INTO INDIVIDUAL PHOSPHATIDES IN SLICES FROM DIFFERENT AREAS OF GUINEA PIG BRAIN

Abstract— Incorporation of 32P into phosphatidic acid was significantly increased in the presence of an appropriate concentration of norepinephrine, either 0.1 mm, or 1 mm, or both, in slices of guinea pig cerebellar cortex, olfactory bulbs, cerebral cortex, hypothalamus and thalamus; it was not significantly affected at either concentration of norepinephrine in slices of corpus striatum and the posterior and anterior colliculi. Incorporation of 32P into phosphatidylinositol was significantly increased in the presence of norepinephrine in a concentration of either 0.1 mm, or 1 mm, or both, in three of the areas studied—the olfactory bulbs, cerebral cortex, and thalamus. There was no significant effect of 0.1 mm‐norepinephrine on 32P incorporation into phosphatidylcholine or phosphatidylethanolamine plus phosphatidylserine in any of the areas studied. Norepinephrine (1 mm) significantly inhibited 32P incorporation into phosphatidylcholine in cerebral cortex, hypothalamus, corpus striatum and anterior colliculus; 32P incorporation into phosphatidylethanolamine plus phosphatidylserine was inhibited by 1 mm‐norepinephrine in cerebral cortex, hypothalamus, and posterior and anterior colliculi. In slices of cerebellar cortex, 0.1 mm and 1 mm‐norpinephrine did not significantly affect either the specific activity or the level of nucleotide ∼ P in the tissue. The physiological significance of changes in phosphatide metabolism in response to neurotransmitters in the central nervous system is discussed. Copyright © 1969, Wiley Blackwell. All rights reserved