The aim of this study was to analyze the effects of chronic administration of the ß-adrenoceptor agonist clenbuterol (2 mg/kg body weight/day for a period of 30 days) on the major contractile protein (myosin) in the left ventricular muscle of the adult mouse heart. Separation of myosin heavy chain (MHC) isoforms on 7.5 % glycerol SDS-PAGE and subsequent quantification of the gels by laser densitometry showed a 6.5-fold increase in the ß-isoform of MHC in the clenbuterol-treated group. The ?: ß ratio of these two isoforms in the control group was 98.16±0.14 %: 1.83±0.14 %, whereas in the treated group it was 88.05±1.15 %: 11.95±1.15 %. Actomyosin ATPase activity assay demonstrated a significant (20 %) decline in ATPase activity of the tissue in the ß-agonist-treated group. These results suggest that chronic clenbuterol treatment is capable to induced the transformation of MHC isoforms increasing the slow ß-MHC isoform, which may contribute to the altered contractile mechanics of clenbuterol-treated hearts.
- MeSH
- aktomyosin chemie izolace a purifikace MeSH
- dysfunkce levé srdeční komory etiologie farmakoterapie MeSH
- finanční podpora výzkumu jako téma MeSH
- index tělesné hmotnosti MeSH
- klenbuterol aplikace a dávkování terapeutické užití MeSH
- kontrakce myokardu účinky záření MeSH
- myši metabolismus růst a vývoj MeSH
- těžké řetězce myosinu chemie MeSH
- zvířata MeSH
- Check Tag
- myši metabolismus růst a vývoj MeSH
- zvířata MeSH
