Galanin and β-endorphin as feeding regulators in cyprinids:: effect of temperature

The effects of intracerebroventricular (ICV) and intraperitoneal (IP) administration of galanin and beta-endorphin on food intake have been studied in satiated tench held at 21 +/- 2 degrees C. Food intake was evaluated at 0-2 h and 2-8 h after injection, The same treatments were carried out in tench and goldfish acclimated to 10 +/- 1 degrees C. Central administration of either galanin or beta-endorphin significantly increased food intake at 2 h and 8 h after injection in tench acclimated to 21 +/- 2 degrees C, but no change in feeding was observed after IP treatments. Low temperature (10 degrees C) significantly reduced food intake in both tench and goldfish, and neither central nor peripheral administration of galanin or beta-endorphin was found to modify feeding, The results indicate that galanin and opioids play a role in the central regulation of feeding in tench, but the stimulatory effect of these neuropeptides did not reverse the feeding inhibition produced by exposure to low temperature.