Contractile dysfunction in stunned myocardium could result from a decrease in the intracellular free [Ca2+] transient during each beat, a decrease in maximal Ca2+-activated force, or a shift in myofilament Ca2+ sensitivity. We measured developed pressure (DP) at several [Ca]0 (0.5-7.5 mM) in isovolumic Langendorff-perfused ferret hearts at 37 degrees C after 15 min of global ischemia (stunned g...

AIMS Post-systolic wall thickening (PSWT) occurs after aortic valve closure. This waste of thickening does not participate in ejection. PSWT increases with myocardial ischaemia and stunning but the effects of anti-anginal drugs on PSWT during myocardial dysfunction remain unknown. The effects of two heart rate reducing agents, i.e. the beta-blocker atenolol and the selective I(f) current inhibi...

Percussive and electrical stunning are the most promising methods in terms of rendering fish unconscious prior to slaughter. The aim of this study was to determine the effect of these two stunning methods on postmortem muscle changes and meat quality of common carps. The experimental fish were stunned either by percussion (Group 1) or by electrical current application (Group 2), both followed b...

The mechanism of myocardial stunning has been studied extensively in rodents and is thought to involve a decrease in Ca responsiveness of the myofilaments, degradation of Troponin I (TnI), and no change in Ca handling. We studied the mechanism of stunning in isolated myocytes from chronically instrumented pigs. Myocytes were isolated from the ischemic (stunned) and nonischemic (normal) regions ...

BACKGROUND Myocardial preservation during open heart surgery is a subject of intense investigation. A prerequisite for further improvement is a better understanding of the underlying pathophysiologic mechanisms responsible for postoperative myocardial stunning. In this report, we analyzed the role of apoptosis in myocardial stunning. METHODS Myocardial samples were obtained from 11 patients u...

Myocardial blood flow is spatially heterogeneous, reflecting nonuniform oxygen supply. Also, myocardial oxidative metabolism is spatially heterogeneous. The effects of acute ischemia and reperfusion on the relationship between local myocardial blood flow (LMF) and oxidative metabolism are still unknown. LMF was measured in isolated, blood-perfused rabbit hearts using colored microspheres and ox...

Although previous studies suggested that the protection of late preconditioning (PC) against myocardial stunning is mediated by nitric oxide (NO), direct evidence that exogenous administration of NO attenuates myocardial stunning is lacking. Furthermore, although exogenous NO administration was shown to elicit a late PC phase, it is unknown whether NO donors also induce an early PC phase. There...

“Preconditioning with ischemia” (PC) is the phenomenon whereby one or more episodes of brief ischemia paradoxically renders the myocardium resistant to a later, more sustained ischemic insult (1–3). The cardioprotection afforded by brief, transient ischemia is biphasic; a “first window” of protection is manifest within the initial 5 min to approximately 3 h of the PC stimulus, the hallmark of w...

Proteins are no longer just ingredients for biologists: Proteinaceous materials are gradually stepping into the spotlight as highly functional next generation materials, despite the fact that “material science” has previously mainly been explored by chemists. In the September 16th issue of Journal of American Chemical Society, Tezcan and co-workers report an interesting methodology to prepare a...