Rice coleoptiles, renowned for anoxia tolerance, were hypoxically pretreated, excised, 'healed', and then exposed to a combination of anoxia and pH 3.5. The putative acid load was confirmed by net effluxes of K(+) to the medium, with concurrent net decreases of H(+) in the medium, presumably mainly due to H(+) influx. Yet the coleoptiles survived the combination of anoxia and pH 3.5 for at leas...

Catecholaminergic polymorphic ventricular tachycardia (CPVT) causes sudden cardiac death due tomutations in cardiac ryanodine receptors (RyR2), calsequestrin, or calmodulin. Flecainide, a class I antiarrhythmic drug, inhibits Na and RyR2 channels and prevents CPVT. The purpose of this study is to identify inhibitory mechanisms of flecainide on RyR2. RyR2 were isolated from sheep heart, incorpor...

Catecholaminergic polymorphic ventricular tachycardia (CPVT) causes sudden cardiac death due tomutations in cardiac ryanodine receptors (RyR2), calsequestrin, or calmodulin. Flecainide, a class I antiarrhythmic drug, inhibits Na and RyR2 channels and prevents CPVT. The purpose of this study is to identify inhibitory mechanisms of flecainide on RyR2. RyR2 were isolated from sheep heart, incorpor...

Thermal activation of the visual pigment constitutes a fundamental constraint on visual sensitivity. Its electrical correlate in the membrane current of dark-adapted rods are randomly occurring discrete "dark events" indistinguishable from responses to single photons. It has been proposed that thermal activation occurs in a small subpopulation of rhodopsin molecules where the Schiff base linkin...

The regulation of the cytoplasmic and vacuolar pH values (pHc and pHv) in sycamore (Acer pseudoplatanus L.) cells was analyzed using 31P and 13C nuclear magnetic resonance spectroscopy. Suspension-cultured cells were compressed in the NMR tube and perfused with the help of an original arrangement enabling a tight control of the pH (external pH, pHe) of the carefully oxygenated circulating nutri...

Catecholaminergic polymorphic ventricular tachycardia (CPVT) causes sudden cardiac death due to mutations in cardiac ryanodine receptors (RyR2), calsequestrin, or calmodulin. Flecainide, a class I antiarrhythmic drug, inhibits Na(+) and RyR2 channels and prevents CPVT. The purpose of this study is to identify inhibitory mechanisms of flecainide on RyR2. RyR2 were isolated from sheep heart, inco...

Proteolytic activity is compared in anther extracts from Petunia parodii fertile and cytoplasmic male sterile lines. It is characterized relative to developmental stage of the anthers, effect of variable incubation times, pH of isolation buffers, and degradation of marker proteins. In fertile anthers, proteolytic activity increases at the end of microsporogenesis and peaks early in microgametog...

Protons are utilized for various biological activities such as energy transduction and cell signaling. For construction of the bacterial flagellum, a type III export apparatus utilizes ATP and proton motive force to drive flagellar protein export, but the energy transduction mechanism remains unclear. Here, we have developed a high-resolution pH imaging system to measure local pH differences wi...

Two members of the B-cell associated 31 (BAP31) family are found in humans; BAP29 and BAP31. These are ubiquitously expressed receptors residing in the endoplasmic reticulum. BAP31 functions in sorting of membrane proteins and in caspase-8 mediated apoptosis, while BAP29 appears to mainly corroborate with BAP31 in sorting. The N-terminal half of these proteins is membrane-bound while the C-term...