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

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services 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 Google Scholar Google Scholar Articles by Palaniyandi, S. S. Articles by Aizawa, Y. Search for Related Content PubMed PubMed Citation Articles by Palaniyandi, S. S. Articles by Aizawa, Y.

---

ORIGINAL RESEARCH ARTICLE

Chymase Inhibition Reduces the Progression to Heart Failure After Autoimmune Myocarditis in Rats

Suresh S. Palaniyandi^*,,1, Yusuke Nagai^*,1, Kenichi Watanabe^*,2, Meilei Ma^*, Punniyakoti T. Veeraveedu^*, Paras Prakash^*, Fadia A. Kamal^*, Yuichi Abe^*, Ken’ichi Yamaguchi, Hitoshi Tachikawa, Makoto Kodama and Yoshifusa Aizawa

^* Department of Clinical Pharmacology, Niigata University of Pharmacy and Applied Life Sciences, Niigata City, 956-8603, Japan; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305; Department of Homeostatic Regulation and Development, Niigata University School of Medicine, Niigata City, 951-8510, Japan; and First Department of Medicine, Niigata University School of Medicine, Niigata City, 951-8510, Japan

To whom requests for reprints should be addressed at ² Department of Clinical Pharmacology, Niigata University of Pharmacy and Applied Life Sciences, Niigata City, 956-8603, Japan. E-mail: watanabe{at}nupals.ac.jp

Chymase has been known as a local angiotensin II–generating enzyme in the cardiovascular system in dogs, monkeys, hamsters, and humans; however, recently it was reported that chymase also has various other functions. Therefore, we decided to examine whether the inhibition of chymase improves disease conditions associated with the pathophysiology of dilated cardiomyopathy in rats and its possible mechanism of action as rat chymase is unable to produce angiotensin II. We examined the effect of TY-51469, a novel chymase inhibitor (0.1 mg/kg/day [group CYI-0.1, n = 15] and 1 mg/kg/day [group CYI-1, n = 15]), in myosin-immunized postmyocarditis rats. Another group of myosin-immunized rats was treated with vehicle (group V, n = 15). Age-matched normal rats without immunization (group N, n = 10) were also included in the study. After 4 weeks of treatment, we evaluated cardiac function; area of fibrosis; fibrogenesis; levels of transforming growth factor (TGF)-ß1 and collagen III; hypertrophy and its marker, atrial natriuretic peptide (ANP); and mast cell activity. Survival rate and myocardial functions improved dose-dependently with chymase inhibitor treatment after myosin immunization. A reduction in the percent area of myocardial fibrosis, fibrogenesis, myocardial hypertrophy, and mast cell activity along with a reduction in TGF-ß1, collagen III, and ANP levels in the myocardium were noted in postmyocarditis rats that received chymase inhibitor treatment. The treatment also decreased myocardial aldosterone synthase levels in those animals. Inhibition of chymase reduces the pathogenesis of postmyocarditis dilated cardiomyopathy and progression to heart failure by preventing the pathological remodeling and residual inflammation in rats.

Key Words: chymase inhibitor • cardiomyopathy • postmyocarditis rats • mast cells