HCO3- absorption and its association with Na+ absorption has been studied in the rat jejunum in vivo, using a single-pass perfusion technique. The method of disequilibrium pH, the only valid way of demonstrating jejunal H+ secretion, was used to distinguish between an HCO3- pump and H+ secretion as the mechanism of HCO3- absorption. HCO3- stimulated Na+ absorption; Na+ deletion inhibited HCO3 a...

a total of 148 groundwater samples were collected from bore wells from thirumanimuttar sub-basin for two seasons to identify major geochemical process activated to alter groundwater chemistry. the study revealed relationships with the lithology and anthropogenic process. groundwater in the region was dominated by na – ca – mg and cl and hco3 types. the (ca +mg) versus tz+ plot for both seas...

Although endogenous CO2 hydration and serosal HCO3- are both known to contribute to the high rates of intestinal HCO3- secretion important to marine fish osmoregulation, the basolateral step by which transepithelial HCO3- secretion is accomplished has received little attention. Isolated intestine HCO3- secretion rates, transepithelial potential (TEP) and conductance were found to be dependent o...

Fluoride (F) is an essential element of drinking water for human health, especially bone development and enamel creation. However, if the fluoride content in higher than 1.5 mg/L or lower 0.5 mg/L, it will cause endemic diseases, such as dental fluorosis. There are two main hydrogeological characteristics: properties water-bearing rocks groundwater conditions controlled guide basin. The geother...

Membrane transport pathways for transplacental transfer of CO2/HCO3 were investigated by assessing the possible presence of a Cl/HCO3 exchange mechanism in the maternal-facing membrane of human placental epithelial cells. Cl/HCO3 exchange was tested for in preparations of purified brush border membrane vesicles by 36Cl tracer flux measurements and determinations of acridine orange fluorescence ...

In order to clarify the interaction between CO2 diffusion and HCO3- shift in the red blood cell (RBC), HCO3- shift was measured by using a stopped flow method combined with fluorometry. When HCO3- entered the RBC, the intracellular PCO2 increased, causing a secondary outflow of CO2. Conversely, when HCO3- ions flowed out of the RBC, the resulting decrease of PCO2 caused an inward CO2 diffusion....