AJP - Renal Physiology, Vol 246, Issue 1 12-F20, Copyright © 1984 by American Physiological Society

ARTICLES

Abnormalities in glomerular function in rats developing spontaneous hypertension

J. R. Dilley, C. T. Stier Jr and W. J. Arendshorst

Clearance and micropuncture studies were conducted on 6-wk-old spontaneously hypertensive rats (SHR) of the Okamoto-Aoki strain and normotensive Wistar-Kyoto rats (WKY) under euvolemic conditions. Mean arterial pressure in SHR was elevated by 18 mmHg and their kidneys were vasoconstricted with reduced blood flow; resistances in preglomerular vessels and efferent arterioles were elevated 2.8 and 2 times, respectively, above WKY values. Whole kidney glomerular filtration rate (GFR) and single nephron glomerular filtration rate (SNGFR), based on fluid collection from either proximal or distal convolutions, were 25-30% lower in SHR. Fractional reabsorptions of fluid load by the proximal convoluted tubule (43%) and by the loop of Henle (52-55%) were similar in both groups. Accordingly, SHR exhibited less fluid delivery from the proximal convolution (8 vs. 12 nl/min) and to the distal convolution (3 vs. 5 nl/min). Glomerular dynamics in hypertensive and normotensive strains were characterized by filtration pressure disequilibrium. Estimated glomerular capillary pressure and mean effective ultrafiltration pressure were similar in SHR and WKY. SHR had a lower glomerular ultrafiltration coefficient than WKY (0.011 vs. 0.016 nl X s-1 X mmHg-1), which, combined with a lower glomerular plasma flow (41 vs. 73 nl/min), quantitatively accounted for the lower SNGFR in 6-wk-old SHR. These findings document important differences in renal function in young SHR compared with WKY that may participate in the development of hypertension.

This article has been cited by other articles:

				A. T. Layton, L. C. Moore, and H. E. Layton Multistability in tubuloglomerular feedback and spectral complexity in spontaneously hypertensive rats Am J Physiol Renal Physiol, July 1, 2006; 291(1): F79 - F97. [Abstract] [Full Text] [PDF]

				S. W. Kim, W. Wang, T.-H. Kwon, M. A. Knepper, J. Frokiaer, and S. Nielsen Increased expression of ENaC subunits and increased apical targeting of AQP2 in the kidneys of spontaneously hypertensive rats Am J Physiol Renal Physiol, November 1, 2005; 289(5): F957 - F968. [Abstract] [Full Text] [PDF]

				P. Meneton, X. Jeunemaitre, H. E. de Wardener, and G. A. Macgregor Links Between Dietary Salt Intake, Renal Salt Handling, Blood Pressure, and Cardiovascular Diseases Physiol Rev, April 1, 2005; 85(2): 679 - 715. [Abstract] [Full Text] [PDF]

				C. M. Sorensen, P. P. Leyssac, O. Skott, and N.-H. Holstein-Rathlou NO mediates downregulation of RBF after a prolonged reduction of renal perfusion pressure in SHR Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2003; 285(2): R329 - R338. [Abstract] [Full Text] [PDF]