HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted 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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lopaschuk, G. D. Articles by Tsang, H. Search for Related Content PubMed PubMed Citation Articles by Lopaschuk, G. D. Articles by Tsang, H. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 262, Issue 8, 3615-3619, Mar, 1987

Regulation of pantothenic acid transport in the heart. Involvement of a Na+-cotransport system

GD Lopaschuk, M Michalak and H Tsang

Pantothenic acid transport was studied in the isolated perfused rat heart and isolated sheep cardiac sarcolemmal vesicles. In the perfused heart, pantothenic acid transport was significantly greater if hearts were perfused as working hearts rather than Langendorff hearts, but was unaffected by the perfusion substrates used (11 mM glucose or 1.2 mM palmitate). Uptake rates of pantothenic acid in working hearts are dependent on perfusate concentrations of pantothenic acid (a Vmax of 418 nmol/g dry weight/30 min and a Km for pantothenic acid of 10.7 mircoM were obtained). Reduction in perfusate Na+ concentration from 145 to 105 mM (the Na+ was replaced with 40 mM choline) resulted in a small but significant decrease in pantothenic acid uptake. At 145 mM Na+, addition of a mixture of amino acids, whose uptake is Na+- dependent, resulted in a significant decrease in pantothenic acid uptake by the heart (173 +/- 5 to 132 +/- 12 nmol/g dry weight). If an inward Na+ gradient in isolated, purified sarcolemmal vesicles, was imposed, a rapid uptake of pantothenic acid was observed. Uptake rates are markedly reduced if Na+ was replaced by equimolar concentrations of K+ or if external Na+ was reduced below 40 mM. In the presence of Na+, increasing pantothenic acid concentrations resulted in an increase in pantothenic acid uptake by the vesicles. Combined, these data demonstrate that pantothenic acid is transported across the myocardial sarcolemmal membrane by a Na+-dependent mechanism, which may be common to a number of small molecules.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				R. B. Calder, R. S. B. Williams, G. Ramaswamy, C. O. Rock, E. Campbell, S. E. Unkles, J. R. Kinghorn, and S. Jackowski Cloning and Characterization of a Eukaryotic Pantothenate Kinase Gene (panK) from Aspergillus nidulans J. Biol. Chem., January 22, 1999; 274(4): 2014 - 2020. [Abstract] [Full Text] [PDF]