Effect of oleoyl-esterone treatment on the expression of β1- β2- and β3-adrenoreceptors in rat adiopose tissues

Adult female rats received a constant i.v. infusion of oleoyl-estrone (3.5 mu mol/kg day) in a lipidic suspension for 14 days. On days 0 (no treatment), 3, 6, 10 and 14, as well as on day 14 for controls (receiving only the lipid); the rats were killed and the expression of the beta (1)-, beta (2)- and beta (3)-adrenoceptor genes, in brown adipose tissue and in subcutaneous and periovaric white adipose tissue, were measured by RNA protection assay, and compared with that of cyclophyllin. The beta (3)-adrenoceptor was the most expressed in all adipose tissues, whereas beta (2) was the less expressed in brown adipose tissue. Oleoyl-estrone significantly, but moderately, increased the expression of beta -adrenoceptors in the three adipose tissues: beta (1) increased in subcutaneous, beta (2) and beta (3) in periovaric and beta (3) in brown adipose tissue. Oleoyl-estrone also decreased beta (3) expression in subcutaneous white adipose tissue. On day 10, adipocytes isolated from periovaric white adipose tissue of oleoyl-estrone-treated rats showed higher cAMP response to an isoproterenol challenge than the controls. The mechanism by which oleoyl-estrone elicits the wasting of fat reserves could be mediated by adrenergic pathways, at least in part.