Effect of cholecystokinin tetrapeptide amide on the metabolism of 5-hydroxytryptamine in the rat brain.
The effect of cholecystokinin tetrapeptide amide (CCK-4) on the content of 5-hydroxytryptamine (5-HT) and its major metabolite, 5-hydroxyindole-3-acetic acid (5-HIAA), was studied in various regions of the brain of rat. After intracerebroventricular administration of CCK-4, the content of 5-HT decreased, while the content of 5-HIAA increased in some areas. These changes were marked 30 min after the injection and relatively small doses (10 and 100 ng) of CCK-4 produced a pronounced effect, but larger doses (1 and 10 micrograms) were less effective. The ratio of 5-HIAA/5-HT increased significantly in most regions of the brain, except in the striatum and the olfactory tubercle. The results indicate that exogenous CCK-4 in small doses stimulates the metabolism of 5-HT in the brain of rat.
Itoh
S
S
Shionogi Research Laboratories, Osaka, Japan.
Takashima
A
A
Katsuura
G
G
D000818:Animals; D001921:Brain / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005755:Gastrins / Q000494:pharmacology*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007276:Injections, Intraventricular; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D013758:Tetragastrin / Q000008:administration & dosage / Q000494:pharmacology*
D005755:Gastrins; D013758:Tetragastrin; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid