Effect of naloxone and antidepressants on hyperphagia produced by peptide YY.
Central injection of peptide YY (PYY) elicits a powerful feeding response with a short latency in satiated rats. Because of this effect, PYY has been implicated as a neurochemical signal in bulimia nervosa. Serotonin agonists and opioid antagonists induce anorectic effects upon feeding behavior in humans and animals. Therefore, to investigate a possible interaction between PYY-induced eating and these anorexigenic agents rats were given injections of either naloxone (100 micrograms/3 microliters, ICV, and 10 mg/kg, SC), fluoxetine (3-30 micrograms/3 microliters and 5-10 mg/kg, IP), or clomipramine (3-30 micrograms/3 microliters and 5-10 mg/kg, IP) prior to fourth ventricular injections of PYY (15 micrograms/18 microliters). Central and peripheral naloxone and IP but not central injections of fluoxetine blocked PYY-induced intake. Clomipramine had no effect. This suggests that PYY-stimulated feeding may require the action of endogenous opioids and may be inhibited by serotonergic function.
Hagan
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MM
Department of Psychology, University of Texas, El Paso 79968-0553.
Moss
D E
DE
D000818:Animals; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002997:Clomipramine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects*; D005260:Female; D005473:Fluoxetine / Q000494:pharmacology; D005768:Gastrointestinal Hormones / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology*; D019894:Peptide YY; D010455:Peptides / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D000928:Antidepressive Agents; D005768:Gastrointestinal Hormones; D010455:Peptides; D005473:Fluoxetine; D019894:Peptide YY; D009270:Naloxone; D002997:Clomipramine