ササキ　ダイスケ   Sasaki Daisuke   佐々木　大輔    所属   医学研究科 医学研究科 (医学部医学科をご参照ください)    職種   特任助教
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Auto-oscillations of skinned myocardium correlating with heartbeat.
掲載誌名	正式名：Journal of muscle research and cell motility 略　 称：J Muscle Res Cell Motil ISSNコード：01424319/01424319
掲載区分	国外
巻・号・頁	26(2-3),pp.93-101
著者・共著者	Sasaki Daisuke, Fujita Hideaki, Fukuda Norio, Kurihara Satoshi, Ishiwata Shin'ichi
発行年月	2005
概要	Skinned myocardium (or myofibrils) exhibits auto-oscillations of sarcomere length and developed force called SPOC (SPontaneousOscillatoryContraction) under partial activation conditions. In SPOC, each sarcomere repeats the cycle of slow shortening and rapid lengthening, and the lengthening phase propagates sequentially to the adjacent sarcomeres in waves (SPOC wave). In this study, we analyzed the sarcomeric oscillation in SPOC in skinned myocardium of various animal species (rat, rabbit, dog, pig, and cow) with different heart rates. The period of oscillation, the sarcomere shortening velocity, and the velocity of SPOC wave, strongly correlated with the resting heart rate of the animal species. The shortening velocity in particular was proportional to the resting heart rate. We then examined the motile activity of each cardiac myosin by an in vitro motility assay. The sliding velocity of actin filaments, which is an index of the motile activity of myosin, also correlated with the resting heart rate but the relationship was not proportional. As a result, the ratio of sarcomere shortening velocity in SPOC to the sliding velocity of actin filaments was not constant but became higher with a higher heart rate. This suggests that the sarcomere shortening velocity in SPOC is modulated by some additional factors besides the motile activity of myosin, resulting in the proportional relationship between the shortening velocity of the sarcomere and the resting heart rate.
DOI	10.1007/s10974-005-0249-2
PMID	15999228