In this study we investigate the mechanism of intracellular pH change and its role in malignant transformation using the E7 oncogene of human papillomavirus type 16 (HPV16). Infecting NIH3T3 cells with recombinant retroviruses expressing the HPV16 E7 or a transformation deficient mutant we show that alkalinization is transformation specific. In NIH3T3 cells in which transformation can be turned...

Formate stimulates sodium chloride and fluid reabsorption in kidney proximal tubule; however, the exact cellular mechanism of this effect remains unknown. We hypothesized that the primary target of formate is the apical Na(+)/H(+) exchanger. Here, we demonstrate that formate directly enhances the apical Na(+)/H(+) exchanger (NHE3) activity in mouse kidney proximal tubule. In the absence of CO(2...

PURPOSE Hydration and urinary alkalinization are essential for reducing renal dysfunction with high dose methotrexate (HDMTX). This report presents an analysis of institutional methods used to achieve adequate urinary alkalinization and output for patients receiving single agent HDMTX. Renal and metabolic parameters of tolerance were examined. METHODS Medical records of adult patients receivi...

Extracellular acidification induced by retinal horizontal cells has been hypothesized to underlie lateral feedback inhibition onto vertebrate photoreceptors. To test this hypothesis, the H(+)-sensitive fluorophore 5-hexadecanoylaminofluorescein (HAF) was used to measure changes in H(+) from horizontal cells isolated from the retina of the catfish. HAF staining conditions were modified to minimi...

The light-dependent pH changes in the suspending medium of guard cell protoplasts (GCP) from Vicia faba were studied. Upon illumination, the medium was initially slightly alkalinized and then acidified. The extent of alkalinization was lower in CO(2)-free air than in normal air. This initial alkalinization was inhibited by DCMU. Acidification in CO(2)-free air became observable in shorter durat...

Changes in cytoplasmic pH are known to regulate diverse cellular processes and influence neuronal activities. In neurons, the intracellular alkalization is shown to occur after stimulating several channels and receptors. For example, it has previously demonstrated in P19 neurons that a sustained intracellular alkalinization can be mediated by the Na(+)/H(+) antiporter. In addition, the benzodia...

Miyata, Yukio, Shigeaki Muto, Satoru Yanagiba, and Yasushi Asano. Extracellular Cl2 modulates shrinkageinduced activation of Na1/H1 exchanger in rat mesangial cells. Am J Physiol Cell Physiol 278: C1218–C1229, 2000.—To examine the effect of hyperosmolality on Na1/H1 exchanger (NHE) activity in mesangial cells (MCs), we used a pHsensitive dye, 28,78-bis(2-carboxyethyl)-5(6)-carboxyfluorescein-AM...

Formate stimulates sodium chloride and fluid reabsorption in kidney proximal tubule, however, the exact cellular mechanism of this effect remains unknown. We hypothesized that the primary target of formate is the apical Na/H exchanger. Here we demonstrate that formate directly enhances the apical Na/H exchanger (NHE3) activity in mouse kidney proximal tubule. In the absence of CO2/HCO3, additio...