Satiation due to CCK-8 derivative infusion into VMH is related to a specific macronutrient selection.
Diet self-selection from carbohydrate, protein and lipid offered simultaneously was studied in adult male rats infused for 8 days with pyroglutamyl-CCK-8 (pGlu-CCK-8) (0.8 pmol/hr), a derivative of the COOH-terminal octapeptide of cholecystokinin (CCK), or vehicle bilaterally into the ventromedial hypothalamus (VMH). Infusion with pGlu-CCK-8 markedly decreased total daily energy intake mainly due to a suppressed carbohydrate intake. Both pGlu-CCK-8 and vehicle infusions caused a nonspecific decrease in protein intake, but the vehicle infusion caused a compensatory increase in lipid intake as well as carbohydrate intake, so their total energy intake was well maintained. These results suggest that the process of infusion into the VMH elicited itself a suppressive effect on protein intake, but that pGlu-CCK-8 infusion elicited a more specific suppressive effect on carbohydrate intake and, to a lesser extent, on lipid intake. These results also support the prediction that centrally administered CCK may suppress food intake and show in addition that such a suppression occurs selectively. The similarities and the differences in the patterns of macronutrient selection produced by vehicle of pGlu-CCK-8 infusions into the VMH provide further evidence of the unique functions of VMH and CCK in the feeding process.
Thibault
L
L
Division of Protein Metabolism, Osaka University, Japan.
Nagai
K
K
Hashida
A
A
Yanaihara
N
N
Nakagawa
H
H
D000818:Animals; D001931:Brain Mapping; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D005518:Food Preferences / Q000187:drug effects*; D008297:Male; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D011919:Rats, Inbred Strains; D012527:Satiation / Q000187:drug effects*; D012844:Sincalide / Q000031:analogs & derivatives* / Q000494:pharmacology; D014697:Ventromedial Hypothalamic Nucleus / Q000187:drug effects*
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; C065492:sincalide, pGlu-; D012844:Sincalide; D011761:Pyrrolidonecarboxylic Acid