Ryanodine Decreases Internal Ca2+ Recirculation Fraction of the Canine Heart as Studied by Postextrasystolic Transient Alternans.
نویسندگان
چکیده
منابع مشابه
Exponential fitting of postextrasystolic potentiation may underestimate the cardiac Ca2+ recirculation fraction: a theoretical analysis.
The recirculation fraction of intramyocardial Ca(2+) (RF) has conventionally been obtained from the monotonic decay of postextrasystolic potentiation (PESP). The used assumption is that the decay is exponential. However, we have found that PESP usually decays in alternans even at spontaneous heart rates (>100 beats/min) in excised, cross-circulated canine heart preparations under normal coronar...
متن کاملTemperature-dependent postextrasystolic potentiation and Ca recirculation fraction in canine hearts
JU MIZUNO,1,2 JUNICHI ARAKI,1 SHUNSUKE SUZUKI,2 SATOSHI MOHRI,1,3 TAKESHI MIKANE,2 JUICHIRO SHIMIZU,1 HIROMI MATSUBARA,3 MASAHISA HIRAKAWA,2 TOHRU OHE,3 AND HIROYUKI SUGA1,4 Departments of 1Cardiovascular Physiology, 2Anesthesiology and Resuscitology, and 3Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry, Okayama, 700-8558; and 4National Cardiovascular Cente...
متن کاملTemperature-dependent postextrasystolic potentiation and Ca(2+) recirculation fraction in canine hearts.
We have found that cardiac temperature proportionally changes O(2) cost of contractility, defined as O(2) consumption for myocardial total Ca(2+) handling normalized to contractility in terms of the end-systolic pressure-volume ratio (maximal elastance, E(max)), in the canine left ventricle (temperature sensitivity, Q(10) = 2). We have separately found that a decrease in the recirculation fract...
متن کاملPostextrasystolic contractility normally decays in alternans in canine in situ heart.
We have reported that the postextrasystolic (PES) potentiation of left ventricular (LV) contractility usually decays in alternans at heart rates above 80-100 beats/min in the canine excised, cross-circulated heart. We examined whether the PES contractility would also decay in alternans even in the canine in situ heart presumably more physiological than the excised heart. In anesthetized, ventil...
متن کاملPostextrasystolic contractile decay always contains exponential and alternans components in canine heart.
In isolated, blood-perfused canine hearts, postextrasystolic potentiation (PESP) decays monotonically after a noncompensatory pause following a spontaneous extrasystole (ES). The monotonic PESP decay yields myocardial internal Ca(2+) recirculation fraction (RF). We have found that after a compensatory pause (CP), PESP decays in alternans, consisting of an exponential and a sinusoidal decay comp...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Japanese Journal of Physiology
سال: 1997
ISSN: 0021-521X
DOI: 10.2170/jjphysiol.47.521