Opposite effects on feeding of suprachiasmatic nucleus neuropeptide Y administration in rats.
The effects of injecting or infusing neuropeptide Y (NPY) into the suprachiasmatic nucleus of rats on patterns of individual macronutrient and water intake were examined during the following 2 h and also across 12 and 24 h light/dark cycles. Increased total energy intake (218 and 170%) and energy intake from the dextrin/sucrose diet (499 and 247%) were observed in the 2 h following injection of 100 pmol NPY at early light and early dark, respectively, and in the following 24 h (total energy: 67%, dextrin/sucrose: 73%). Nocturnal casein energy intake was also increased (258%) following NPY injection. Continuous infusion of 10 pmol/h of NPY suppressed nocturnal total energy (36%) and dextrin/sucrose intake (36%) as well as 24 h energy intake from casein (43%). These results demonstrate divergent effects of NPY subsequent to different mode of administration.
Thibault
L
L
School of Dietetics and Human Nutrition, McGill University, Quebec, Canada. cxlt@musica.mcgill.ca
Komenami
N
N
D000818:Animals; D003624:Darkness; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D004435:Eating / Q000187:drug effects* / Q000528:radiation effects; D002149:Energy Intake / Q000187:drug effects* / Q000528:radiation effects; D005518:Food Preferences / Q000187:drug effects* / Q000528:radiation effects; D008027:Light; D008297:Male; D009478:Neuropeptide Y / Q000494:pharmacology*; D017440:Photoperiod; D051381:Rats; D017208:Rats, Wistar; D013493:Suprachiasmatic Nucleus / Q000187:drug effects*; D013997:Time Factors
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D009478:Neuropeptide Y