Posterior isolated gills of Neohelice (Chasmagnathus) granulatus were symmetrically perfused with hemolymph-like saline of varying [HCO3-] and pH. Elevating [HCO3-] in the saline from 2.5 to 12.5 mmol/l (pH 7.75 in both cases) induced a significant increase in the transepithelial potential difference (Vte), a measure of ion transport. The elevation in [HCO3-] also induced a switch from acid sec...

influence extracellular acid–base status in brachyuran decapod crustaceans (Truchot, 1973; Truchot, 1981; Truchot, 1992; Mangum et al., 1976; Henry and Cameron, 1982; Wheatly, 1985). Although the underlying mechanisms and the physiological consequences remain unclear, the basis for the relationship between acid–base status and ion regulation can be attributed to the catalysed hydration of CO2 b...

Exposure to elevated silver (as AgNO3) concentrations (6-9 microM) in seawater was associated with comparably high silver concentrations in the intestinal fluids of the lemon sole (Parophrys vetulus), and a tendency for reduced drinking rate. The effects of silver on intestinal ion and acid-base regulation were studied using in situ perfusion of the intestine. Intestinal net Cl- uptake was redu...

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...

Na+:H+ and Cl-:HCO3- exchange are localized, respectively, to basolateral (blLPM) and canalicular (cLPM) rat liver plasma membranes. To determine whether these exchangers play a role in bile formation, we examined the effect of a choleretic agent, ursodeoxycholate (UDCA), on these exchange mechanisms. 22Na (1 mM) and 36Cl (5 mM) uptake was determined using outwardly directed H+ and HCO3- gradie...

HENRIK VORUM, TAE-HWAN KWON, CHRISTIAAN FULTON, BRIAN SIMONSEN, INYEONG CHOI, WALTER BORON, ARVID B. MAUNSBACH, SØREN NIELSEN, AND CHRISTIAN AALKJÆR Department of Medical Biochemistry, Department of Cell Biology, Institute of Anatomy, and Department of Physiology, University of Aarhus, DK-8000 Aarhus C, Denmark; and Department of Cellular and Molecular Physiology, Yale University, New Haven, Co...

Properties of adenosine triphosphatases (ATPases) in the choroid plexus of rabbit cerebral ventricles were investigated using tissue homogenates and subcellular fractions. Na,K-ATPase or HCO3-ATPase activity of choroid plexus was significantly lower than that of the brain or the kidney, respectively. Among the homogenates of choroid plexus from the lateral, third and fourth ventricles, there we...

Growth factors stimulate Na+/H+ exchange activity in many cell types but their effects on acid secretion via this mechanism in renal tubules are poorly understood. We examined the regulation of HCO3- absorption by nerve growth factor (NGF) in the rat medullary thick ascending limb (MTAL), which absorbs HCO3- via apical membrane Na+/H+ exchange. MTAL were perfused in vitro with 25 mM HCO3- solut...

Carlin, Ryan W., Rebecca R. Quesnell, Ling Zheng, Kathy E. Mitchell, and Bruce D. Schultz. Functional and molecular evidence for Na -HCO3 cotransporter in porcine vas deferens epithelia. Am J Physiol Cell Physiol 283: C1033–C1044, 2002. First published May 22, 2002; 10.1152/ ajpcell.00493.2001.—This study focused on the role of sodium-bicarbonate cotransporter (NBC1) in cAMP-stimulated ion tran...

Patterns of salivary HCO3 secretion vary and depend on species and gland type. However, the identities of the transporters involved in HCO3 transport and the underlying mechanism of intracellular pH (pHi) regulation in the salivary glands still remain unclear. In this experiment, we examined the expression of the Na/HCO3 cotransporter(NBC) and its role in pHi regulation in guinea pig salivary g...