Electrophysiological Characteristics Of Cardiac Myocytes In Simulated Weightless Rats

While astronauts return from the weightlessness into 1-G environment of the Earth, obvious cardiovascular dysfunction is generally present among them during early postflight stage, which may lead to significant orthostatic intolerance. It is now well recognized that multiple mechanisms might be involved in and the single factor of decrease in blood volume could not explain it satisfactorily. In the past time most studies have focused on the effects of short-term weightlessness on cardiovascular system, however, in recent years changes in the structure and function of heart/cardiac muscle induced by real/simulated weightlessness have been repeatedly reported. Therefore, the role played by cardiac adaptive changes in the genesis of postflight orthostatic intolerance should not be ignored. Hence, more attention has been paid to studies on effects of real/simulated weightlessness on cardiac muscle. Although there have been much work on myocardial structure and function, reports on electrophysiological changes induced by real/simulated weightlessness are very rare.Some of postflight echocardiographic data from astronauts, magnetic resonance imaging data obtained from a bed-rest study, as well as the...