Renin Secretion and Renal Vascular Resistance Following Prolonged Administration of Desoxycorticosterone (Doc) in Rats Drinking Normal Saline

Abstract

1. The effect of long-term administration of desoxycorticosterone (DOC)-saline on arterial blood pressure, renal vascular resistance and renin secretion rate was studied in the rat. 2. Renin secretion rate and peripheral plasma renin activity was markedly reduced in the DOC-saline treated rats. Renal vascular resistance was comparable to that found in a corresponding control group. Responsiveness to isoprenaline suggested that the beta-adrenoceptor mediating renin release was grossly intact. 3. A significant rise in blood pressure occurred in only 50% of the treated animals: However, no differences in weight gain, renal vascular resistance or renin levels were apparent when compared with animals which remained normotensive. 4. These findings indicate that suppression of renin secretion during prolonged DOC-saline administration cannot be directly attributed to changes in arterial pressure, renal vascular resistance or beta-adrenoceptor sensitivity.