Acute kidney sympathectomy alters renal vascular responses to graded angiotensin II infusion in rat: The role of mas receptor and gender

Abstract

Background We examined the roles of the Mas receptor (MasR) and acute renal sympathetic nerve ablation on renal hemodynamic and kidney function responses to angiotensin II (Ang II) in male and female rats. Methods Mean arterial pressure (MAP), renal blood flow (RBF), renal vascular resistance (RVR) and kidney function responses to Ang II with or without acute renal denervation (ARDN) were measured in a vehicle or A779 (MasR antagonist) treated male and female anesthetized rats. Results Baseline MAP, RBF, and RVR did not differ significantly between ARDN and intact groups. After Ang II administration, MAP increased with no significant difference between ARDN and intact groups. RBF and RVR responses to Ang II were different significantly between intact and ARDN male rats treated with saline (P < 0.05), but such results were observed in female rats treated with A779 (P < 0.05). ARDN increased urine flow and fractional sodium excretion in both genders significantly (P < 0.05), but after Ang II injection, these two parameters did not show significant differences between intact and ARDN rats. Conclusion MasR antagonist contributes to provide different RBF and RVR responses to Ang II between ARDN and intact female rats.