Glomerular Hyperfiltration in Hypertensive Fawn-Hooded Rats

The glomerular filtration rate (GFR), effective renal plasma flow (ERPF), systolic blood pressure (SBP) and urinary protein excretion (UpV) were determined in 12-week-old male rats of the spontaneously hypertensive Fawn-Hooded (FH) strain. These data were compared with those of either age-matched or weight-matched male, normotensive Wistar Albino Glaxo (WAG) rats. The GFR was significantly higher in FH rats than in both WAG control groups. In contrast, the ERPF did not differ between the FH and WAG rats. Thus, a higher filtration fraction was present in the FH rats. As no differences were found in the total number of glomeruli per kidney comparing FH and WAG rats, the high GFR was not due to an increase in the number of glomeruli. The SBP and the UpV were significantly higher in FH rats than in WAG rats. To our opinion, the arterial hypertension associated with glomerular hyperfiltration proteinuria suggests the presence of glomerular hypertension in FH rats.