The effect of attenuating age‐related increases in blood pressure in male and female spontaneously hypertensive rats on the kidney (1136.17)

Abstract

The kidney is critical in the long‐term control of blood pressure, and renal inflammation has been linked to the progression of hypertension. Previous experiments have shown a sex difference in protein excretion and the renal immune cell profile: male SHRs have greater indices of renal injury and more pro‐hypertensive renal T helper17 cells (Th17) while females had more BP‐lowering T regulatory cells (Tregs). Male and female SHR were randomized to receive tap water (vehicle) or the BP‐lowering drugs, hydrochlorothiazide and reserpine, in drinking water from 5 to 12 weeks of age. BP was measured by tail cuff, and kidneys were isolated for flow cytometric analysis of T cells. Treatment attenuated age‐related increases in BP in males (174±4 vs. 137±4 mmHg, p<0.05) and females (132±4 vs 161±1 mmHg, p<0.05). However, treatment did not significantly change metabolic parameters, urinary electrolyte excretion (Na+, K+, Cl‐) or urinary protein excretion in either sex. In contrast, although attenuation of the development of hypertension did not significantly change the renal T cell profile in male SHR, females exhibited a decrease in renal Tregs (p=0.0091) and Th17 (p=0.0203) counts which abolished the sex differences observed in the renal T cell profile of vehicle‐treated rats.