Angiotensin II may act as an angiogenic anf growth promoting factor on different cell types. To assess the role of angiotensin II on the compensatory renal response of the remnant kidney to unilateral nephrectomy (UNX), we measured renin, angiotensinogen, and angiotensin II type I receptor (AT1) mRNA levels as well as angiotensin II receptor density in 2 groups of 7 Sprague-Dawley rats 7 days after either shamp operation or UNX, Following UNX, the ratio of kidney weight to body weight (KW/BW) increased from 0.38 +/- 0.01 to 0.46 +/- 0.01 % (p < 0.01). Neither renin (kidney) or angiotensinogen (kidney and liver) mRNA levels, determined by slot blot hybridization, changed after UNX. Angiotensin II receptor density was determined using an I-125-Sar1-Ile8 Ang II in situ receptor binding assay on fixed kidney sections. Binding specificity was verified using unlabeled Sar1-Ang II. Glomerular angiotensin II receptor density did not change significantly after UNX, nor did AT1 receptor mRNA. Thus, these data do not support a critical role for angiotensin II in the compensatory renal growth following uninephrectomy.
