Hydroponic culture solutions containing bicarbonate (HCO3 ) may be used to screen crops such as soybeans (Glycine max) for resistance to iron (Fe) deficiency or chlorosis. Some successful methods use sodium bicarbonate (NaHCO3) in combination with elevated partial pressures of carbon dioxide (CO2) to buffer pH and elevate bicarbonate. Replacing NaHCO3 with magnesium bicarbonate [Mg(HCO3)2] as t...

Most marine teleosts defend blood pH during high CO2 exposure by sustaining elevated levels of HCO3(-) in body fluids. In contrast to the gill, where measures are taken to achieve net base retention, elevated CO2 leads to base loss in the intestine of marine teleosts studied to date. This loss is thought to occur through transport pathways previously demonstrated to be involved with routine osm...

Global CO2 level presently recorded at 400 ppm is expected to reach 550 ppm in 2050, an increment likely to impact plant growth and productivity. Using targeted LC-MS and GC-MS platforms we quantified 229 and 29 metabolites, respectively in a time-course study to reveal short-term responses to different concentrations (1, 3, and 10 mM) of bicarbonate (HCO3-) under light and dark conditions. Res...

Intensive algal cultivation usually requires a high flux of dissolved inorganic carbon (Ci) to support productivity, particularly for high density algal cultures. Carbon dioxide (CO2) enrichment can be used to overcome Ci limitation and enhance productivity of algae in intensive culture, however, it is unclear whether algal species with the ability to utilise bicarbonate (HCO3 (-)) as a carbon ...

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...

AIMS Intracellular pH (pHi), an important modulator of cardiac function, is normally regulated to within narrow limits (7.1-7.2). In adult ventricular cell pairs, localized cellular pHi disturbances are removed by sarcolemmal acid/base transporters, but can also be dissipated (diluted) across gap junctions, aboard mobile buffers such as CO2/HCO3- and histidine-containing dipeptides (HCDPs). In ...

The NBCn1 Na(+)/HCO3(-) cotransporter catalyzes the electroneutral movement of 1 Na(+):1 HCO3(-) into kidney cells. We characterized the intracellular pH (pHi) regulation in human embryonic kidney cells (HEK) subjected to NH4Cl prepulse acid loading, and we examined the NBCn1 expression and function in HEK cells subjected to 24-h elevated Pco2 (10-15%). After acid loading, in the presence of HC...

The effects of hypercapnia (1% CO2), and the independent effects of changes in extracellular pH (pHe), PCO2 and [HCO3-] on intracellular pH (measured by the DMO method) and lactate metabolism (measured by utilization of 14C-labelled lactate), were examined in rainbow trout hepatocytes in vitro. Simulated uncompensated hypercapnia (high PCO2, low pHe, moderately increased [HCO3-] led to a substa...

We investigated membrane voltage and intracellular pH (pHi) in cultured human ciliary muscle cells using a cell line (H7CM) and primary-cultured human ciliary muscle cells. 1) Resting potential was 58.9 +/- 1.0 mV in H7CM cells and 61.9 +/- 1.4 mV in primary cultures. The following data are from H7CM cells, but results from primary cultures were basically similar. 2) In HCO3(-)-CO2-buffered sol...

Cyclic AMP stimulates HCO3 secretion and Cl self-exchange in rabbit cortical collecting tubule. We found that varying peritubular [Cl] changed the Cl self-exchange rate with saturation kinetics (Km, 3-4 mM). HCO3 secretion also showed saturation kinetics as a function of mean luminal [Cl] (Km, 4-11 mM). Both Cl self-exchange and Cl-HCO3 exchange thus appear to be carrier-mediated. Addition/remo...