This Article Full Text Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ho, C. S. Articles by Swaminathan, R. Search for Related Content PubMed PubMed Citation Articles by Ho, C. S. Articles by Swaminathan, R. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB DIGOXIN DOPAMINE OUABAIN SODIUM

(Hypertension. 1997;30:1544-1548.)
© 1997 American Heart Association, Inc.

Articles

Effect of Carbidopa on the Excretion of Sodium, Dopamine, and Ouabain-Like Substance in the Rat

Chung Shun Ho; Asif Butt; Yemane K. Semra; ; R. Swaminathan

From the Department of Chemical Pathology, Prince of Wales Hospital, Shatin, NT, Hong Kong (C.S.H.) and the Department of Chemical Pathology, UMDS, Guy's & St Thomas' Hospital, London, UK (A.B., Y.K.S., R.S.).

Correspondence to Prof R. Swaminathan, Department of Chemical Pathology, United Medical & Dental Schools, St Thomas' Hospital, London, SE1 7EH UK. E-mail r.swaminathan{at}umds.ac.uk

Abstract The effect of carbidopa, a competitive inhibitor of dopamine synthesis on the excretion of sodium, dopamine (DA), and endogenous sodium transport inhibitor (ESTI), was examined in rats on normal and high salt diets for 7 days. ESTI activity was measured (1) as ouabain-like substance (OLS) by radioimmunoassay using an antibody raised against ouabain, (2) by inhibition of purified Na⁺,K⁺-ATPase activity (ATPI), and (3) as digoxin-like substance (DLS) using a commercial digoxin assay. The OLS immunoassay was validated against rubidium transport studies. High salt diet caused an increase in OLS and ATPI but not DLS. Sodium excretion in rats on normal sodium intake was not affected by carbidopa treatment but was significantly lower in the high sodium diet group during the first 5 days of the study. In the low salt group, carbidopa treatment caused significant increases in OLS. We conclude that ESTI (measured as OLS) and DA are important in the natriuresis of salt loading.

Key Words: dopamine • sodium • ouabain • carbidopa • sodium transport inhibitor, endogenous

This article has been cited by other articles:

				A. Y. Bagrov, J. I. Shapiro, and O. V. Fedorova Endogenous Cardiotonic Steroids: Physiology, Pharmacology, and Novel Therapeutic Targets Pharmacol. Rev., March 1, 2009; 61(1): 9 - 38. [Abstract] [Full Text] [PDF]