Introduction: The sympathetic nervous system and renin-angiotensin system (RAS) are the most pivotal vasoactive systems in regulating renal hemodynamics. The main objective of this study was to determine the role of angiotensin II (Ang II) type 1 receptor (AT1R) antagonist on renal hemodynamics responses to Ang 1-7 infusion in innervated and denervated rats. Methods and Materials: Male and female Wistar rats were subjected to unilateral nephrectomy. Four weeks later, they were divided into two groups. Renal innervated or acutely denervated groups. Each group was divided into four subgroups: male and female rats were anesthetized & treated with vehicle and received Ang 1-7 or rats were treated with losartan and received Ang 1-7. Then, a catheter was placed into the left carotid and femoral arteries. The jugular vein was cannulated for vehicle or losartan and Ang1-7 infusion by two micro- injection pumps. Then mean arterial pressure (MAP), renal blood flow (RBF), renal perfusion pressure (RPP), and renal vascular resistance (RVR) responses to Ang 1-7 (100, 300, and 1000 ng/kg/min) were measured at controlled RPP. Results: Basal MAP, RPP, RBF, and RVR were not significantly different between the intact and denervated groups. Losartan decreased MAP, RPP, and RVR in innervated and denervated male and female rats significantly (P<0.0001), but RBF was increased only in innervated and denervated female rats (P<0.004). However, after Ang 1-7 administration, RBF response to Ang 1-7 infusion was significantly different between intact and denervated male rats treated with losartan (P<0.04). Such response was not observed in female rats. Conclusion: These data indicate the synergistic effect of losartan and Ang 1-7 on increased RBF in the presence of renal sympathetic nerves in male rats.
Kharazmi F, Pourshanazari A, Nematbakhsh M. The role of AT1 receptor antagonist on renal hemodynamic responses to angiotensin 1-7 administration in acute sympathectomic male and female rats. Koomesh 2023; 25 (5) :410-410 URL: http://koomeshjournal.semums.ac.ir/article-1-8578-en.html