We evaluated the effects of acetazolamide on Na+-HCO3- cotransport in basolateral membrane vesicles isolated from the rabbit renal cortex. Na+ uptake stimulated by an imposed inward HCO3- gradient was not significantly reduced by 1.2 mM acetazolamide, indicating that acetazolamide does not directly inhibit Na+-HCO3- cotransport. 4,4'-Diisothiocyanostilbene-2,2'-disulfonate (DIDS)-sensitive Na+-...

[1] Marine phytoplankton have the potential to significantly buffer future increases in atmospheric carbon dioxide levels. However, in order for CO2 fertilization to have an effect on carbon sequestration to the deep ocean, the increase in dissolved CO2 must stimulate primary productivity; that is, marine phototrophs must be CO2 limited [Riebesell et al., 1993]. Estimation of the extent of bica...

Studies were performed on canine cardiac Purkinje fibers to evaluate the effects of acidosis and bicarbonate (HCO3) on action potential repolarization. Extracellular pH (pHe) was reduced from 7.4 to 6.8 by increasing carbon dioxide (CO2) concentration from 4 to 15% in a HCO3-buffered solution or by NaOH titration in a Hepes-buffered solution. Both types of acidosis produced a slowing of the rat...

When Zostera marina was irradiated after a period of darkness, initiation of photosynthetic O2 evolution occurred in two phases. During a lag phase, lasting 4 to 5 min, photosynthesis was supported by a diffusive entry of CO2. Photosynthesis then rapidly increased to its full rate. Tris buffer, at a concentration of 50 mm, completely inhibited this increase without affecting CO2-supported photo...

In this study, it is shown how to transfer tared aliquots of (HCO3 + CO2)-containing luminal fluids directly into the mercury-sealed chamber of a modified Van Slyke apparatus and how to obtain direct as well as indirect manometric determinations of dissolved CO2 ([CO2]f) in each aliquot of such fluids. It is next shown that the pattern of in vitro luminal acidification in an isolated turtle bla...

BACKGROUND The objective of this study was to examine the correlation between arterial blood gas (ABG) and peripheral venous blood gas (VBG) samples for all commonly used parameters in patients admitted to a medical intensive care unit (ICU). METHODS A single-center, prospective trial was carried out in a medical ICU in order to determine the level of correlation of ABG and peripheral VBG mea...

A quantitative analysis of O2 and CO2 transport was conducted in resting and exercising rainbow trout, and these data were used to quantify the magnitude of coupling between O2 and CO2 exchange, in vivo. The release of Bohr protons during haemoglobin-oxygenation was non-linear over the Hb-O2 equilibrium curve used in trout subjected to different levels of sustained exercise. At low swimming spe...

A new in vitro assay was developed and critically characterized to measure the rate of CO2 excretion by trout red blood cells (RBCs) from HCO3- in their natural plasma under normal in vivo conditions of acid-base status. The assay is based on the addition of [14C]bicarbonate to the whole blood and collection of the resultant 14CO2 in the overlying gas phase. The assay simulates the exposure of ...

ID No: 65 ABSTRACT This research studies the self-healing potential of early cracks in cement-based materials incorporating carbonic anhydrase (CA) bacteria. CA bacteria can accelerate the CO2 hydrated reaction then transfer CO2 to HCO3 which can react with soluble Ca(OH)2 on the surface of specimens. Calcium carbonate deposits because of the reaction of HCO3 with Ca.This research studies the s...

A Na(+)-HCO3- coinflux carrier and the Na(+)-H+ antiport have both been shown to contribute to recovery from intracellular acidosis in cardiac tissue. We have investigated the participation of these mechanisms as well as metabolite (lactate and CO2) washout in the recovery of pHi after myocardial ischemia. Isovolumic ferret hearts were Langendorff-perfused with either HCO3(-)-buffered or nomina...