ALDOSTERONE AND HYPERTENSION IN OVARIECTOMIZED FEMALE DAHL SALT SENSITIVE RATS ON LOW SALT DIET

Abstract

Blood pressure (BP) increases in postmenopausal women. Ovariectomy increases BP in female Dahl salt sensitive rats (DS) even if maintained on low salt diet. OVX also have higher aldosterone (ALDO) levels and develop more renal injury than intact females. Since ALDO can cause increases in BP and renal injury, the hypothesis was tested that the mineralcorticoid receptor antagonist, eplerenone (EPL), would reduce BP and renal injury in OVX DS. Female DS, 16 weeks of age, kept on low salt diet from birth, were divided into four groups: intact females (INT), intact females + eplerenone (100mg/kg/day by gavage; INT/EPL), ovariectomized females (OVX) and OVX + eplerenone (OVX/EPL) for 10 days. BP was measured by telemetry; renal injury was evaluated by urinary albumin excretion. Sgk‐1 and NGAL expression, indexes of renal tubular damage, were measured in kidney cortex by western blot. Plasma ALDO levels were also measured. As shown in the table below, OVX DS had higher BP and albuminuria than INT, and EPL reduced both only in OVX. Sgk‐1 and NGAL renal expression was higher in OVX than INT, and was reduced with EPL. These data show that increased aldosterone plays an important role in the higher BP and renal injury in OVX DS.*p<0.05, compared with INT control; #p<0.05, compared with control OVX.The data show that aldosterone plays an important role in the hypertension and renal injury in OVX DS rats. These data suggest that in postmenopausal women, aldosterone may play a role in mediating the increase in blood pressure.