Down-regulation of Na+/K+-ATPase alpha(2) isoform in denervated rat vas deferens

Down-regulation of Na+/K+-ATPase alpha(2) isoform in denervated rat vas deferens

Author Quintas, LEM Google Scholar
Caricati-Neto, A. Google Scholar
Lafayette, SSL Google Scholar
Jurkiewicz, A. Google Scholar
Noel, F. Google Scholar
Institution Universidade Federal do Rio de Janeiro (UFRJ)
Universidade Federal de São Paulo (UNIFESP)
Abstract In the rat vas deferens, an organ richly innervated by peripheral sympathetic neurons, we have demonstrated recently the expression of alpha(1) and alpha(2), but not alpha(3) isoforms of the a subunit of Na+/K+-ATPase (EC, a membrane-bound enzyme of vital function for living cells (Noel et al., Biochem Pharmacol 55: 1531-1535, 1998). in the present work, we characterized, qualitatively and quantitatively, Na+/K+-ATPase a isoforms in denervated rat vasa deferentia. [H-3]Ouabain binding at concentrations defined for high-affinity isoforms (alpha(2) and/or alpha(3)) detected only one class of specific binding sites in control (C) and denervated (D) vas deferens. Although the dissociation constant was similar for both groups [K-d = 138 +/- 14 nM (C) and 125 +/- 8 nM (D)], a marked decrease in density was observed after denervation [716 +/- 81 fmol(.)mg protein(-1) (C) and 445 +/- 34 fmol(.)mg protein(-1) (D), P < 0.05]. in addition, western blotting revealed that denervated vasa deferentia produce the alpha(1) and alpha(2) isoforms but not alpha(3), just as we reported for the controls previously (Noel et al., Biochem Pharmacol 55: 1531-1535, 1998). Densitometric analysis showed a decrease of the alpha(2) isoform by about 4094 in denervated organs, in very good agreement with what was shown with the [H-3]ouabain binding technique, but no significant change in oil isoform density. Truncated alpha(1) (alpha(1)T), an isoform suggested to exist in the guinea pig vas deferens, was not detected. Altogether, our results demonstrated that Na+/K+-ATPase alpha(2) is down-regulated after sympathetic denervation of the rat vas deferens. (C) 2000 Elsevier Science Inc.
Keywords vas deferens
Na+-K+-exchanging ATPase
Language English
Date 2000-09-15
Published in Biochemical Pharmacology. Oxford: Pergamon-Elsevier B.V., v. 60, n. 6, p. 741-747, 2000.
ISSN 0006-2952 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 741-747
Access rights Closed access
Type Article
Web of Science ID WOS:000088679300002

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