Single Nephron Hemodynamics in Spontaneously Hypertensive Rats

This study was designed to determine whether glomerular hypertension develops as a function of age in the spontaneously hypertensive rat (SHR). Male SHR and age-matched Wistar-Kyoto (WKY) normotensive controls were divided into three groups for measurements of whole kidney and single nephron hemodynamics at 5, 10, and 15 months of age. As reported previously, SHR developed significant proteinuria which was predominantly an albuminuria, after 5 months of age. There were no differences in whole kidney or single nephron glomerular filtration rates between SHR and WKY. Afferent glomerular capillary hydraulic pressure (PGC) was slightly increased in SHR compared with WKY at 10 months of age. At 15 months of age, PGC in SHR was significantly lower than WKY. Our studies indicate that increased capillary pressure is not a major factor in the development and progression of renal injury in the spontaneously hypertensive rat.