Central administration of beta-endorphin increases food intake in goldfish: pretreatment with the opioid antagonist naloxone.
The effect of intraperitoneal or intracerebroventricular beta-endorphin administration on food intake has been studied in satiated goldfish. Food intake was evaluated at different time intervals after injections, 0-2, 2-8 and 0-8 h. The 0.1 and 1 micrograms doses of beta-endorphin intracerebroventricularly administered induced an increase in food intake during the first 2 h postinjection, while no modifications on feeding were observed in the next 6 h. These same doses of beta-endorphin used increased cumulative food intake at 8 h postinjection. In contrast, intraperitoneal injection of 1 micrograms of beta-endorphin did not modify food intake in any of the studied time intervals. Naloxone, an opioid antagonist, attenuated the beta-endorphin-induced feeding increase. These results suggest that opioids may play a role in modulation of feeding central regulation, acting via opioid receptors in goldfish.
de Pedro
N
N
Departamento de Biología Animal II (Fisiología Animal), Facultad de Ciencias Biológicas, Universidad Complutense, Madrid, Spain.
Delgado
M J
MJ
Alonso-Bedate
M
M
D000704:Analysis of Variance; D000818:Animals; D004347:Drug Interactions; D004435:Eating / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects; D006054:Goldfish; D006801:Humans; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism; D001615:beta-Endorphin / Q000008:administration & dosage / Q000494:pharmacology*
D011957:Receptors, Opioid; D009270:Naloxone; D001615:beta-Endorphin