LETTER TO THE EDITOR: REPLY
NADPH oxidose in the failins human heart: Reply
Thomas Munzel, MD* and
Ascan Warnholtz, MD*
* Universitätsklinikum Hamburg-Eppendorf, Medizinische Klink III, Schwerpunkte Kardiologie und Angiologie, Martinistrasse 52, 20246 Hamburg, Germany
muenzel{at}uke.uni-hamburg.de
In our recent editorial (1) we commented on the expression and activity of the NAD(P)H oxidase subunit gp91phox isoform in the failing human heart reported by Heymes et al. (2). We also stated that this evidence was provided for the first time, not mentioning the article by Krijnen et al. (3), which was published in the March issue of the Journal of Clinical Pathology. One simple reason for that was that our editorial comment was already in press when the report from Krijnen et al. appeared. In that study the investigators describe the existence of Nox 2 (gp91phox) in normal human cardiomyocytes and an up-regulation of the expression as assessed by Western blotting technique and by immunohistochemistry in viable and jeopardized cardiomyocytes of freshly infarcted areas. Since this report was published in March, we agree that the study was indeed the first to comment on the expression of the NAD(P)H oxidase subunit Nox2 in human cardiomyocytes. Although the researchers have observed an increase in Nox2 in myocardial areas subject to acute myocardial infarction (AMI), one cannot really compare this situation with that of chronic congestive heart failure. Acute myocardial infarction is always accompanied by an acute and severe inflammatory response, and in the studies by Krijnen et al.3 no data were provided as to whether these patients had clinical signs of acute heart failure. Thus, the correspondent may agree that Heymes et al. (2) provided the first evidence for a lack of changes in the expression of Nox2 but an increase in the activity of the enzyme in patients with severe chronic congestive heart failure.
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References
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1. Warnholtz A, Munzel T. The failing human heart: another battlefield for the NAD(P)H oxidase? J Am Coll Cardiol. 2003;41:2172–2174[Free Full Text]
2. Heymes C, Bendall JK, Ratajczak P, et al. Increased myocardial NADPH oxidase activity in human heart failure. J Am Coll Cardiol. 2003;41:2164–2171[Abstract/Free Full Text]
3. Krijnen PAJ, Meischl C, Hack CE, et al. Increased Nox2 expression in human cardiomyocytes after acute myocardial infarction. J Clin Pathol. 2003;56:194–199[Abstract/Free Full Text]
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