The study aims to identify the correlation between arterial and venous blood gas variables, in patients with metabolic acidosis secondary to renal failure and/or diabetic ketoacidosis(DKA). Paired arterial and venous blood samples of 100 patients, with metabolic acidosis resultant to renal failure and/or diabetic ketoacidosis during 2009-2011, were analyzed and the correlation between the varia...

[1] While much of the dissolved organic carbon (DOC) within rivers is destined for mineralization to CO2, a substantial fraction of riverine bicarbonate (HCO3 ) flux represents a CO2 sink, as a result of weathering processes that sequester CO2 as HCO3 . We explored landscape-level controls on DOC and HCO3 flux in subcatchments of the boreal, with a specific focus on the effect of permafrost on ...

The choroid plexus epithelium of the brain ventricular system produces the majority of the cerebrospinal fluid and thereby defines the ionic composition of the interstitial fluid in the brain. The transepithelial movement of Na+ and water in the choroid plexus depend on a yet-unidentified basolateral stilbene-sensitive Na+-HCO3- uptake protein. Reverse transcriptase-polymerase chain reaction (R...

Ureagenesis in the liver consumes up to 1,000 mmol of HCO3-/day in humans as a result of 2NH4+ + 2HCO3- --> urea + CO2 + 3H2O. Whether the liver contributes to the regulation of acid-base equilibrium by controlling the rate of ureagenesis and, therefore, HCO3- consumption in response to changes in plasma acidity has not been adequately evaluated in humans. Rates of ureagenesis were measured in ...

Furla, Paola, Denis Allemand, and Maria-Novella Orsenigo. Involvement of H1-ATPase and carbonic anhydrase in inorganic carbon uptake for endosymbiont photosynthesis. Am J Physiol Regulatory Integrative Comp Physiol 278: R870–R881, 2000.—Symbiotic cnidarians absorb inorganic carbon from seawater to supply intracellular dinoflagellates with CO2 for their photosynthesis. To determine the mechanism...

Na depletion inhibits electroneutral Na-Cl absorption in intact tissues and Na/H exchange in apical membrane vesicles (AMV) of rat distal colon. Two anion (Cl/HCO3 and Cl/OH) exchanges have been identified in AMV from surface cells of rat distal colon. To determine whether Cl/HCO3 and/or Cl/OH exchange is responsible for vectorial Cl movement, this study examined the spatial distribution and th...

This study provides the first information about pHi regulatory mechanisms in human retinal pigment epithelium (RPE). The experiments were carried out on fresh explant tissues from adult donor and fetal eyes, and pHi was measured using fluorescence microscopy techniques and the pH-sensitive dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. In adult donor RPE, the resting pHi is 7.30 +/- 0.14 ...

The effect of 24 h of unilateral ureteral obstruction on HCO3 reabsroption and urinary acidification was studied in dogs. The postobstructed kidney (EK) had a significantly lower glomerular filtration rate and renal plasma flow than the contralateral kidney (CK). Urinary pH prior to HCO3 loading was significantly higher in the EK as was maximal HCO3 reabsorption. Saline loading depressed HCO3 r...

Pulmonary vasoconstriction is influenced by inactivation of nitric oxide (NO) with extracellular superoxide (O2-*). Because the short-lived O2-* anion cannot diffuse across plasma membranes, its release from vascular cells requires specialized mechanisms that have not been well delineated in the pulmonary circulation. We have shown that the bicarbonate (HCO3-)-chloride anion exchange protein (A...

Bicarbonate provides the dominant pH buffer of the cochlear fluids. In the present study, perilymph bicarbonate concentration was manipulated during which endocochlear potential, cochlear fluids pH and cochlear sensitivity to sounds were monitored. Perilymphatic perfusion of medium containing elevated HCO3, at higher pH than normal, produced a decrease in endolymph pH. Similarly, perfusion of n...