Although an increase in cytosolic pH (pHi) caused by Na+/H+ exchange enhances Ca2l mobilization in platelets stimulated by low concentrations of thrombin [Siffert & Akkerman (1987) Nature (London) 325, 456-458], studies using fluorescent indicators for pHi (BCECF) and [Ca2"]i (fura2) suggest that Ca2" is mobilized while the cytosolic pH decreases. Several lines of evidence indicate that the ini...

Extracellular H(+) has been hypothesized to mediate feedback inhibition from horizontal cells onto vertebrate photoreceptors. According to this hypothesis, depolarization of horizontal cells should induce extracellular acidification adjacent to the cell membrane. Experiments testing this hypothesis have produced conflicting results. Studies examining carp and goldfish horizontal cells loaded wi...

Major brands of cocoa powder products present in the Spanish market were analyzed for monomeric flavanols [(+)-catechin and (-)-epicatechin] and flavonols [quercetin-3-glucuronide, quercetin-3-glucoside (isoquercitrin), quercetin-3-arabinoside, and quercetin]. In addition, the influence of the manufacturing process of cocoa powder products, in particular, the alkalinization treatment ( Dutching...

We examined the effect of depolarization on intracellular pH (pHi) of normal (pHi approximately 7.37) and acidified (pHi 5.90-6.70) frog semitendinosus muscle using microelectrodes. A small bundle was superfused with a Na(+)-free buffered solution (10 mM HEPES, 100% O2, pH 7.35) containing either 2.5 or 25 mM K+. An NH4Cl prepulse was used to lower pHi. At normal pHi, depolarization usually pro...

BACKGROUND The purpose of this study was to determine the effectiveness of a single early instillation of mitomycin C (MMC) after transurethral resection of bladder tumor (TURBT) together with urinary alkalinization in patients with low-risk non-muscle-invasive bladder cancer (NMIBC). METHODS Between February 2006 and November 2010, patients diagnosed as having a primary bladder tumor were ra...

We have used dialyzed squid axons to characterize the ouabain- and bumetanide-insensitive Na efflux components and their relation to the operation of the Na/Ca exchange mechanism. In axons dialyzed with solutions containing nearly physiological concentrations of K, Na, and Mg, three components of the Na efflux can be distinguished: Cai-activated, Cao-dependent Na efflux ("reverse" Na/Ca exchang...

Elevated plasma levels of inorganic phosphate (Pi) are harmful, causing, among other complications, vascular calcification and defective insulin secretion. The underlying molecular mechanisms of these complications remain poorly understood. We demonstrated the role of Pi transport across the plasmalemma on Pi toxicity in INS-1E rat clonal β cells and rat pancreatic islet cells. Type III sodium-...