- 作者: Yuanyuan Jia; Sarah Akerman; Xupei Huang
- 作者服務機構: Department of Biomedical Science, and Center for Molecular Biology and Biotechnology, Florida Atlantic University, Boca Raton, Fla., USA
- 中文摘要: --
- 英文摘要: To study the genomic physiology of cardiac myofibrilproteins in the heart, we have successfully created a car-diac troponin I (cTnl; a myofibril protein) gene knockoutmouse model using gene targeting techniques. The phe-notype of the cTnl gene knockout mouse is a cardiomy-opathy with diastolic dysfunction resulting in suddendeath in neonates. In the present studies, energy metab-olism was analyzed in myocardial cells from cTnl-nullhearts. Myofibril MgATPase activities were determinedin myocardial cells from either wild-type or cTnl mutantmouse hearts. Furthermore, the quantity and quality ofthe mitochondria in wild-type and cTnl mutant animalswere counted and analyzed. Our results demonstratethat damaged relaxation and increased Ca -indepen-dent force production in cTnl-null hearts is in part relatedto the increased myofibril MgATPase activities accompa-nied by an increase in mitochondria quantity and mito-chondrial ATPase activities. These data indicate that car-diomyopathies with diastolic dysfunction are differentfrom cardiomyopathies caused by systolic dysfunction.The former involves the damage of cardiac relaxationdue to increased MgATPase activities and increasedCa -independent force production inside of myofila-ments, while the latter involves the damage of systoliccontraction due to decreased MgATPase activities anddecreased force production.
- 中文關鍵字: --
- 英文關鍵字: --