title: Age and nutritional state influence the effects of cholecystokinin on energy balance.
abstract: Cholecystokinin (CCK) is anorexic, irrespective whether it is applied intraperitoneally (IP) or intracerebroventricularly (ICV) in male Wistar rats. The metabolic effects depend on the route of administration: by the IP route it elicits hypothermia (presumably by type-1 receptors, CCK1R-s), while ICV administration is followed by fever-like hypermetabolism and hyperthermia via activation of CCK2R-s, which latter response seems to be most important in the postprandial (compensatory) hypermetabolism. The efficacy of the IP injected CCK varies with age: it causes strong anorexia in young adult 4 and 6-months old and again in old rats (aged 18-24 months), but the middle-aged (12-month old) ones seem to be resistant to this effect. Such pattern of effects may contribute to the explanation of age-related obesity observed in middle-aged animals as well as to the aging anorexia and loss of body weight in old ones. Diet-induced obesity accelerates the appearance of CCK-resistance as well as the return of high sensitivity to CCK in further aging, while chronic calorie-restriction prevents the development of resistance, as if the speed of the age-related regulatory changes was altered by the nutritional state. The effects of ICV applied CCK also change with age: the characteristic anorexic and hypermetabolic/hyperthermic effects can be observed in young adult rats, but the effects gradually and monotonically decline with age and disappear by the old age of 24 months. These disparate age-related patterns of CCK efficacy upon peripheral or central administration routes may indicate that although both peripheral and central CCKR-s exert anorexic effects, they may have dissimilar roles in the regulation of overall energy balance.
authors.affiliation: Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Hungary. Electronic address: marta.balasko@aok.pte.hu.
authors.forename: M
authors.initials: M
authors.lastname: Balaskó
authors.forename: I
authors.initials: I
authors.lastname: Rostás
authors.forename: N
authors.initials: N
authors.lastname: Füredi
authors.forename: A
authors.initials: A
authors.lastname: Mikó
authors.forename: J
authors.initials: J
authors.lastname: Tenk
authors.forename: P
authors.initials: P
authors.lastname: Cséplő
authors.forename: M
authors.initials: M
authors.lastname: Koncsecskó-Gáspár
authors.forename: S
authors.initials: S
authors.lastname: Soós
authors.forename: M
authors.initials: M
authors.lastname: Székely
authors.forename: E
authors.initials: E
authors.lastname: Pétervári
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D000855:Anorexia / Q000139:chemically induced / Q000503:physiopathology; D001833:Body Temperature Regulation / Q000187:drug effects / Q000502:physiology; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D031204:Caloric Restriction; D002766:Cholecystokinin / Q000008:administration & dosage / Q000502:physiology*; D059305:Diet, High-Fat; D004435:Eating / Q000187:drug effects / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D009752:Nutritional Status / Q000502:physiology*; D009765:Obesity / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002766:Cholecystokinin
keywords: Aging; Calorie-restriction; Cholecystokinin; Food intake; Metabolic rate; Obesity