AJP - Renal Physiology, Vol 252, Issue 1 131-F137, Copyright © 1987 by American Physiological Society
Analysis of renal function in the two-kidney Goldblatt model
F. B. Gabbai, L. C. Gushwa, O. W. Peterson, C. B. Wilson and R. C. Blantz
We analyzed the renal functional responses in all rats 4-6 wk after
application of a clip to one renal artery and maintained on either a normal
NaCl-intake or a NaCl-depletion protocol utilizing both clearance methods
and micropuncture evaluations of glomerular hemodynamics. Although mean
arterial pressure (MAP) rose significantly, the response was quite variable
and the frequency and degree of hypertension independent of NaCl dietary
protocol (142 +/- 7 vs. 137 +/- 6 mmHg, NS). Glomerular filtration rate
(GFR) of the unclipped kidney was well maintained regardless of absolute
MAP, however, GFR in the clipped kidney was somewhat MAP dependent. The
glomerular ultrafiltration coefficient (LpA) was reduced in all clipped
rats independent of MAP and dietary NaCl (0.037 +/- 0.002 vs. 0.063 +/-
0.009 nl X s-1 X mmHg-1, P less than 0.05). Glomerular capillary
hydrostatic (PG) and glomerular capillary hydrostatic gradient (delta P)
were elevated in all clipped rats, regardless of MAP, and to a greater
extent in clipped rats maintained on the NaCl-depletion protocol (PG, 59.6
vs. 53.2, P less than 0.05). Among clipped rats, multiple regression
analysis revealed no correlation between PG or delta P and the degree of
reduction in LpA. The unclipped kidney of the two-kidney, one-clip model is
characterized by uniform reductions in LpA independent of the MAP and awake
blood pressure produced. Although the increase in PG and delta P may
contribute to the reduction in LpA observed, the degree of LpA reduction is
independent of the magnitude of elevation in PG and delta P in clipped
rats.
