AJP - Renal Physiology, Vol 269, Issue 5 710-F717, Copyright © 1995 by American Physiological Society
Kallikrein excretion in Dahl salt-sensitive and salt-resistant rats with native and transplanted kidneys
P. C. Churchill, M. C. Churchill, A. K. Bidani and S. F. Rabito
Department of Physiology, Wayne State University, Detroit, Michigan 48201, USA.
Urinary kallikrein excretion is decreased in Dahl salt-sensitive (S) vs.
salt-resistant (R) rats, and several lines of reasoning suggest not only
that decreased kallikrein excretion is a marker for salt-sensitive
hypertension but also that kallikrein might play a pathogenic role. Because
previous cross-transplantation studies have demonstrated that the kidney's
genotype plays a role in determining the blood pressure of the recipient in
Dahl S and R rats, the present experiments were designed to determine
whether both blood pressure and urinary kallikrein excretion "traveled with
the kidney" in transplantation. The Rapp strains of S and R were maintained
on a low- NaCl (0.13%) diet until kidney transplantation (bilaterally
nephrectomized recipients), at which time the diet was switched to high
NaCl (7.8%). Sixteen days later, blood pressures (tail-cuff
plethysmography) of the cross-transplant groups (R/S and S/R, indicating
kidney genotype/recipient genotype) were nearly identical to each other and
intermediate between the blood pressures of the control groups with
transplanted kidneys (R/R and S/S). Renal function studies, performed on
anesthetized rats 17 days after surgery, demonstrated that R kidneys had
higher glomerular filtration rates, renal plasma flows, and urinary
kallikrein excretion rates than S kidneys. These differences tended to be
preserved in the cross-transplant groups, and therefore they must be
genetically determined intrinsic differences between R and S kidneys. This
was especially striking with respect to urinary kallikrein excretion. The
rank order of urinary kallikrein excretion was R/R = R/S > S/R = S/S,
which implies that it is completely determined by the genotype of the
kidney.(ABSTRACT TRUNCATED AT 250 WORDS)
