Dissemin is shutting down on January 1st, 2025

Published in

Bentham Open, Journal of Epithelial Biology and Pharmacology, 1(2), p. 36-43

DOI: 10.2174/1875044300902010036

Links

Tools

Export citation

Search in Google Scholar

Regulation of Renal LAT2 and 4F2hc Expression by Aldosterone

This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Red circle
Preprint: archiving forbidden
Green circle
Postprint: archiving allowed
Green circle
Published version: archiving allowed
Data provided by SHERPA/RoMEO

Abstract

In the spontaneous hypertensive rat, overexpression of the renal Na +-independent L-amino acid transporter LAT2 is organ specific, precedes the onset of hypertension, correlates negatively with plasma aldosterone, and parallels the enhanced ability to take up L-DOPA and form renal dopamine. The present study evaluated the role of aldosterone on transcript and protein abundance of Na+-independent and Na+-dependent amino acid transporters. Na+-independent heterodimeric amino acid transporters LAT1/4F2hc, LAT2/4F2hc and a Na+-dependent transporter ASCT2 transcript and protein abundance was determined in the renal cortex of normotensive Wistar rats chronically treated with aldosterone (1.5 mg), spironolactone (200 mg) or aldosterone plus spironolactone. Aldosterone significantly increased renal cortical LAT2 mRNA levels (45 % increase), with no changes in LAT1, 4F2hc and ASCT2 transcript levels. The effect of aldosterone upon LAT2 mRNA levels was completely prevented by spironolactone. At the protein level, aldosterone treatment did not significantly affect LAT1 and LAT2 expression, but markedly reduced (51 % decrease) the abundance of 4F2hc and the urinary excretion of dopamine and DOPAC. The effect of aldosterone upon 4F2hc protein abundance was not reversed by spironolactone. Increases in renal LAT2 transcript during chronic treatment with aldosterone occur through a spironolactone-sensitive genomic mechanism. This effect parallels with a decrease in LAT2 functionality, resulting from decreases in 4F2hc protein abundance, which appears to be either a non-genomic effect or an indirect effect of aldosterone. The decrease in LAT2 functionality by aldosterone correlates well with the reduction in urinary dopamine.