Abstract
Free water clearances, stop-flow and retrograde intraluminal infusion techniques were used to identify the renal site of action of Su-15049, an arylcyclohexanone derivative that increases the renal excretion of sodium but not the excretion of potassium. During water diuresis, Su-15049 increased urine volume and the clearance of solute-free water in anesthetized dogs. There was little change in sodium excretion, osmolar clearance, or the clearance of inulin. During the i.v. infusion of Su-15049, the proximal limb of the sodium stop-flow pattern was significantly elevated and there was a concomitant decrease in the maximal inulin urine/plasma ratio. The distal limb of the pattern was not altered significantly. The effects of Su-15049 on the distal potassium stop-flow pattern were variable. When the drug was infused retrogradely through a catheter placed in the renal pelvis, a marked reduction in the excretion of potassium was observed. Our data indicate that the proximal tubule is a primary site of the natriuretic action of Su-15049. However, an effect on the distal tubular transport of sodium cannot be excluded. The potassium-sparing action of the drug is a result of enhanced distal tubular reabsorption of the ion.
Footnotes
- Received October 2, 1972.
- Accepted April 4, 1973.
- © 1972 by The Williams & Wilkins Co.
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|