Some effects of aldosterone on sodium kinetics and distribution in porcine arterial wall.
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.
D000450:Aldosterone / Q000494:pharmacology*; D000818:Animals; D002339:Carotid Arteries / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D007700:Kinetics; D008297:Male; D008954:Models, Biological; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*; D013552:Swine
D000450:Aldosterone; D012964:Sodium; D011188:Potassium