A reexamination of the effects of intracerebroventricular glucocorticoids in adrenalectomized rats.
Several investigators have reported that many of the behavioral and metabolic effects of ADX can be reversed by appropriate levels of glucocorticoids administered either peripherally or centrally. The present studies were conducted to offer a comparison of the effects of orally administered corticosterone (CORT) with ICV glucocorticoids [CORT, CORT acetate, or dexamethasone (DEX)]. Of particular interest were the effects of glucocorticoid treatment on body weight gain and on macronutrient self-selection. Adult male Sprague-Dawley rats were fitted with ICV cannulae and either bilaterally ADX or given sham operations. In the first experiment, ADX animals were initially treated systematically with CORT (20 micrograms/ml in their drinking water). After a wash-out period during which no steroids were administered, ADX rats were given daily ICV CORT injections (100 micrograms/day in 10 microliters). Systemic CORT treatment promotes weight gain and normal food choice patterns in ADX rats. ICV injections failed to promote weight gain in ADX rats, and daily injection of the vehicle promoted a weight loss in sham-operated controls. Four additional experiments were conducted. ADX, glucocorticoid-treated animals and ADX, vehicle-treated controls as well as sham-operated, vehicle-treated controls were used to assess the effects of both steroid and vehicle on body weight gain and dietary selection patterns. ADX ICV-glucocorticoid-treated animals typically failed to gain weight at the rate observed when ADX rats are treated with CORT systematically. Under one condition, ADX-CORT-treated animals gained weight at a rate comparable to untreated controls, but their ICV-injected control group failed to gain weight.(ABSTRACT TRUNCATED AT 250 WORDS)
Kamara
K S
KS
Department of Human Nutrition and Food Systems, University of Maryland, College Park 20742.
Kamara
A K
AK
Castonguay
T W
TW
D000315:Adrenalectomy; D000818:Animals; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D003348:Cortisone / Q000008:administration & dosage / Q000494:pharmacology; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology; D004032:Diet; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000502:physiology; D000431:Ethanol / Q000494:pharmacology; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D014677:Pharmaceutical Vehicles; D051381:Rats; D017207:Rats, Sprague-Dawley
D005938:Glucocorticoids; D014677:Pharmaceutical Vehicles; D000431:Ethanol; D003907:Dexamethasone; D003348:Cortisone