ANGIOTENSIN-II-INDUCED STRUCTURAL AND FUNCTIONAL ALTERATIONS IN SPONTANEOUSLY HYPERTENSIVE RAT-KIDNEY

The purpose of this study was to compare functional and structural cha nges in the kidneys of spontaneously hypertensive (SHR) and Wistar-Kyo to (WKY) rats during prolonged administration of angiotensin II. Rats were pretreated with captopril, and the effects of exogenous angiotens in II (200 ng . kg(-1)min(-1) for 7-14 days sc) on renal hemodynamics and renal vascular structure were examined. Angiotensin II induced sig nificant reductions of renal blood flow and glomerular filtration and increases of renal vascular resistance in SHR but not WKY. Furthermore , angiotensin II induced an increase of the media/lumen ratio in the i nterlobular arteries (0.33 +/- 0.02 to 0.56 +/- 0.02) and arcuate arte ries (0.27 +/- 0.02 to 0.53 +/- 0.07) of SHR without significantly alt ering the media/lumen ratio in the interlobular arteries (0.34 +/- 0.0 3 to 0.34 +/- 0.02) and arcuate arteries (0.30 +/- 0.02 to 0.36 +/- 0. 05) of WKY (two-factor analysis of variance, strain X treatment; P = 0 .0002 for interlobular arteries and P = 0.0319 for arcuate arteries). Results from this study indicate that the SHR kidney is more responsiv e than the WKY kidney to the functional and structural effects of prol onged angiotensin II infusion.