Kallikrein excretion in dahl salt sensitive and salt resistant rats
with native and transplanted kidneys.
Churchill, Paul C., Monique C. Churchill, Anil K. Bidani, and Sara F.
Rabito.
Department of Physiology, Wayne State University, Detroit, Michigan
48201, Department of Internal Medicine, Loyola University and Hines
VA Hospital, Maywood, Illinois 60141, Departments of Anesthesiology,
Cook County Hospital and University of Illinois, Chicago, Illinois
60612
APStracts 2:0109F, 1995.
Urinary kallikrein excretion is decreased in Dahl salt sensitive (S)
versus 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 if 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
(0.13%) NaCl diet until kidney transplantation (bilaterally
nephrectomized recipients), at which time the diet was switched to
high (7.8%) NaCl. 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. Finally, although these intrinsic differences between
the kidneys might play a role in determining blood pressure, they
cannot be the entire explanation, because blood pressures in the
cross-transplant groups were nearly identical. Thus, in conclusion,
extrarenal genetic factors in the recipient also have a decisive role
in control of blood pressure.
Received 7 November 1994; accepted in final form 31 May 1995.
APS Manuscript Number F397-4.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 11 July 1995.