To study both temporal and quantitative effects of hypercapnia on the extent of pH compensation in the arterial blood, specimens of carp (Cyprinus carpio) were exposed to a PCO2 of about 7.5 mmHg (1 mmHg = 133.3 Pa) (1% CO2) in the environmental water for several weeks, and a second group of animals was subjected to an environmental PCO2 of about 37 mmHg (5% CO2) for up to 96 h. A third series ...

These experiments evaluated salt transport processes in isolated cortical thick limbs of Henle (cTALH) obtained from mouse kidney. When the external solutions consisted of Krebs-Ringer bicarbonate (KRB), pH 7.4, and a 95% O2-5% CO2 gas phase, the spontaneous transepithelial voltage (Ve, mV, lumen-to-bath) was approximately mV; the net rate of Cl- absorption (JnetCl) was approximately 3,600 pmol...

The choroid plexus epithelium (CPE) is located in the ventricular system of the brain, where it secretes the majority of the cerebrospinal fluid (CSF) that fills the ventricular system and surrounds the central nervous system. The CPE is a highly vascularized single layer of cuboidal cells with an unsurpassed transepithelial water and solute transport rate. Several members of the slc4a family o...

this paper presents results of hydro-chemical processes controlling groundwater chemical composition, using an integrated application of hierarchical cluster analysis and factor analysis of a major ion data set of groundwater from mighan playa aquifer. cluster analysis classified samples into four clusters(a, b, c and d) according to their dominant chemical composition: cluster a (dominant comp...

Intracellular microelectrode techniques and intracellular pH (pHi) measurements using the fluorescent dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF) were employed to characterize an electrogenic bicarbonate transport mechanism at the apical membrane of the frog retinal pigment epithelium (RPE). Reductions in apical concentrations of both [HCO3]o (at constant Pco2 or pHo) or [Na]o c...

The hypothesis of Cl-/HCO3- exchange across the apical membrane of the epithelial cells of Necturus gallbladder was tested by means of measurements of extracellular pH (pHo), intracellular pH (pHi), and Cl- activity (alpha Cli) with ion-sensitive microelectrodes. Luminal pH changes were measured after stopping mucosal superfusion with a solution of low buffering power. Under control conditions,...

Unidirectional Na and Cl~ fluxes, net fluxes of Na, Cl~, other ions, titratable acid (TA), ammonia and acidic equivalents (net H) across the gills, together with the comparable renal fluxes, were monitored throughout a 24-h period after exhaustive exercise (simple chasing) in the rainbow trout. The gills were the major site of flux. The renal excretion of [TA—HCO3~], ammonia, lactate and most e...

Regulation of intracellular pH (pHi) following acidosis induced by NH4+/NH3 exposures was re-investigated in a crayfish stretch receptor neurone using H+and Na+selective microelectrodes. All experiments were performed in nominally HCO3–/CO2free salines. From studies in Na+-free saline and from electrochemical calculations, we concluded that pHi regulation was dependent on extracellular Na+ conc...

Together, the Na(+)-coupled HCO(3)(-) transporters and the AE family of anion exchangers (i.e., Cl-HCO3 exchangers) comprise the bicarbonate transporter (BT) superfamily. Virtually all BTs are important for the regulation of intracellular pH (pH(i)) in cells throughout the body. Specific BTs also play roles in cell-volume regulation, as well as for the transport of salt and/or acid-base equival...