AJP - Regulatory, Integrative and Comparative Physiology, Vol 244, Issue 4 553-R557, Copyright © 1983 by American Physiological Society
Some effects of aldosterone on sodium kinetics and distribution in porcine arterial wall
J. G. Llaurado, J. A. Madden and G. A. Smith
Transport rate constants for Na+ exchanges and relative Na+ compartment
distribution in isolated pig carotid wall were determined with the aid of
22Na+ as tracer that was continuously washed out. A three-compartment model
consisting of 1) extracellular, 2) intracellular, and 3) subcellular spaces
was found to represent adequately the kinetics of 22Na+. It was found that
d-aldosterone (0.85 X 10(-6) M) added to the incubating medium for 3 h
causes significant changes in two transport rate constants and in the
distribution of sodium within different compartments. Total tissue water,
nonradioactive sodium (tracee), and potassium are not altered by
aldosterone; however, when amounts of Na+ tracee are calculated for each
compartment, aldosterone significantly reduces the amount of Na+ in
compartment 2. Overall, the results indicate that aldosterone induces a
translocation of Na+ into the extracellular space at the expense of the
intracellular space. The findings are interpreted in the light of recent
reports on the role of altered function of the Na+-K+ pump under
aldosterone influence or arterial hypertension.
