title: Elevation of plasma cholecystokinin concentration following a meal is increased by gonadectomy in male cats.
abstract: An overweight or obese body condition commonly develops after gonadectomy (GX) in domestic cats. The cause appears to be a rapid, quantal (approximately 12%), increase in food intake that is sustained and probably mediated by withdrawal of gonadal hormone. Recently, an interaction of gonadal hormone and cholecystokinin (CCK) effectiveness has been suggested. A reduction in the satiating potency of intestinal CCK was presently hypothesized to contribute to the disturbance of food intake control caused by GX in domestic cats. Pre- and post-prandial intestinal CCK secretion as indicated by plasma CCK concentrations were determined in 16 adult male cats (5.1 +/- 0.1 kg) 8 weeks before and 57 weeks after eight of the cats were gonadectomized. During ad libitum intake of a commercial dry, expanded diet, body weight increased from 22% to 28% in gonadectomized cats and was unchanged in intact cats. Baseline CCK concentrations were not different between gonadectomized and intact cats. Amounts of diet ingested during CCK determinations were 15-19% of daily metabolizable energy requirement and were not different between gonadectomized and intact cats. The post-prandial area under the curve (AUC; 0-400 min) CCK concentration increased linearly with meal size (p < 0.01) and was not correlated with body weight. Area under the curve CCK concentration, when normalized for meal size, was 34% greater (p < 0.01) in gonadectomized cats than that in intact cats. The findings indicate GX increases meal-induced intestinal CCK secretion and therefore, do not support the study hypothesis. The findings indicate GX may slow digestion and absorption and attenuate inhibition of food intake by CCK.
authors.affiliation: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, 65211, USA. backusr@missouri.edu
authors.forename: R C
authors.initials: RC
authors.lastname: Backus
authors.forename: M L
authors.initials: ML
authors.lastname: Kanchuk
authors.forename: Q R
authors.initials: QR
authors.lastname: Rogers
mesh_terms: D000818:Animals; D019540:Area Under Curve; D002415:Cats / Q000097:blood* / Q000378:metabolism; D002766:Cholecystokinin / Q000097:blood*; D004435:Eating / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D008297:Male; D009919:Orchiectomy / Q000662:veterinary*; D019518:Postprandial Period; D011897:Random Allocation; D013047:Specific Pathogen-Free Organisms
chemical_list: D002766:Cholecystokinin