The metabolic clearance rate of corticosterone in lean and obese male Zucker rats

Journal Article · Thu Jun 01 00:00:00 EDT 1989 · Metab., Clin. Exp.; (United States)

DOI:https://doi.org/10.1016/0026-0495(89)90212-6· OSTI ID:5933807

White, B D; Corll, C B; Porter, J R

The obese Zucker rat is an animal model of human juvenile-onset obesity. These rats exhibit numerous endocrine and metabolic abnormalities. Adrenalectomy of obese rats has been shown to reduce or reverse several of these abnormalities, thereby implying that corticosterone may contribute to the expression of obesity in this animal. Furthermore, it has been shown that the circadian rhythm of plasma corticosterone is disturbed in obese Zucker rats resulting in elevated morning plasma corticosterone concentrations in obese rats as compared to lean rats. In a effort to better elucidate the mechanism of the elevated morning levels of plasma corticosterone, the metabolic clearance rate of corticosterone was determined in the morning for lean and obese male Zucker rats (12 to 20 weeks). Additionally, the biliary and urinary excretion of labeled corticosterone and/or its metabolites were determined. The metabolic clearance rate of corticosterone was significantly greater in obese rats than in their lean counterparts. Both the metabolic clearance rate and the volume of compartments significantly correlated with body weight. No correlation was found between body weight and the elimination rate constant. The increased metabolic clearance rate of obese rats appeared to be due to an increase in the physiologic distribution of corticosterone and not to an alteration in the enzymes responsible for corticosterone metabolism. It appears that the metabolic clearance rate of corticosterone in obese Zucker rats does not contribute to elevated morning concentrations of plasma corticosterone previously observed in these animals. It suggests that the adrenal corticosterone secretion rate must actually be greater than one would expect from the plasma corticosterone concentrations alone.

• Research Organization: Louisiana State Univ. Medical Center, New Orleans (USA)
• OSTI ID: 5933807
• Journal Information: Metab., Clin. Exp.; (United States), Vol. 38:6
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CORTICOSTERONE
CLEARANCE
ADIPOSE TISSUE
BILE
BIOLOGICAL MODELS
METABOLISM
METABOLITES
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
WEIGHT
ADRENAL HORMONES
ANIMAL TISSUES
ANIMALS
BIOLOGICAL MATERIALS
BODY
BODY FLUIDS
CONNECTIVE TISSUE
CORTICOSTEROIDS
GLUCOCORTICOIDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KETONES
LABELLED COMPOUNDS
MAMMALS
MATERIALS
ORGANIC COMPOUNDS
PREGNANES
RODENTS
STEROIDS
TISSUES
VERTEBRATES
550501* - Metabolism- Tracer Techniques