Effect of serotonergic agents on regional concentrations of somatostatin- and neuropeptide Y-like immunoreactivities in rat brain.
A possible role for neuropeptides in affective disorders is suggested by many investigators. Somatostatin-like immunoreactivity (SS-LI) and neuropeptide Y-like immunoreactivity (NPY-LI) concentrations are demonstrated to be reduced in cerebrospinal fluid from depressed patients. We have shown that long-term treatment with serotonin uptake inhibitors, clomipramine and zimelidine, reduce brain SS-LI concentrations in the rat. We have studied the effect of serotonergic agents on regional brain SS-LI and NPY-LI concentrations in rats. Long-term treatment with 5-hydroxytryptamine (5-HTP), a serotonin precursor, caused reductions in SS- and NPY-LI levels in the hypothalamus. SS- and NPY-LI concentrations in the brain were markedly elevated by treatment with p-chlorophenylalanine, a serotonin synthesis inhibitor. Intracerebroventricular administration of 5,7-dihydroxytryptamine, a serotonin neurotoxin, resulted in elevations of both peptides in the brain. These results suggest a inhibitory role for the serotonergic system in the brain in the regulation of SS and NPY.
Department of Psychiatry, Kobe University School of Medicine, Japan.
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D015116:5,7-Dihydroxytryptamine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D003891:Desipramine / Q000494:pharmacology*; D004334:Drug Administration Schedule; D010134:Fenclonine / Q000008:administration & dosage / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D009478:Neuropeptide Y / Q000032:analysis / Q000378:metabolism*; D009928:Organ Specificity; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000008:administration & dosage / Q000494:pharmacology*; D013004:Somatostatin / Q000032:analysis / Q000378:metabolism*
D009478:Neuropeptide Y; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; D013004:Somatostatin; D010134:Fenclonine; D003891:Desipramine