INDUCTION OF OB GENE-EXPRESSION BY CORTICOSTEROIDS IS ACCOMPANIED BY BODY-WEIGHT LOSS AND REDUCED FOOD-INTAKE

Genetic studies in mice have identified the ob gene product as a poten tial signaling factor regulating body weight homeostasis and energy ba lance. It is suggested that modulation of ob gene expression results i n changes in body weight and food intake, Glucocorticoids are shown to have important metabolic effects and to modulate food intake and body weight, In order to test the hypothesis that these metabolic effects of glucocorticoids are linked to changes in the expression of the ob g ene, ob mRNA levels were evaluated in rats treated with different gluc ocorticosteroids at catabolic doses and correlated to the kinetics of changes in body weight gain and food intake, Results from time course experiments demonstrate that adipose tissue ob gene expression is rapi dly induced by glucocorticosteroids. This induction is followed by a c oncordant decrease in body weight gain and food consumption, These dat a suggest that the catabolic effects of corticosteroids on body weight mass and food intake might be mediated by changes in ob expression, M odulation of ob expression may therefore constitute a mechanism throug h which hormonal, pharmacological, or other factors control body weigh t homeostasis.