Activation of choline acetyltransferase by vasoactive intestinal peptide.
Addition of vasoactive intestinal peptide (VIP) to brain homogenates increased the activity of choline acetyltransferase (ChAT) but not that of acetylcholinesterase or glucose-6-phosphate dehydrogenase. Activity of ChAT was increased in the anterior hypothalamus and in the dorsal and ventral hippocampus, but not in the parietal cortex or posterior hypothalamus. Increased activity occurred rapidly after VIP addition to homogenates and was maximal at 10(-7)M concentration. Kinetic analysis indicates that the Vmax of the enzyme is increased and the Km for choline, but not acetyl-coenzyme A, is decreased in the presence of VIP. Results support a possible VIP-cholinergic interaction in the CNS.
D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051381:Rats; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D014660:Vasoactive Intestinal Peptide; D000242:Cyclic AMP; D005954:Glucosephosphate Dehydrogenase; D002795:Choline O-Acetyltransferase; D000110:Acetylcholinesterase