The activity of pyruvate dehydrogenase complex (PDC) purified from pig kidney cortex was found to be affected by various uni- and bi-valent ions. At a constant strength of 0.13 M at pH 7.8, K+, Na+, Cl-, HCO3- and HPO4(2-) had significant effects on the activity of PDC: Na+, K+ and HPO4(2-) stimulated, but HCO3- and Cl- inhibited. The stimulatory effect of Na+ was mediated by a change in the Vm...

UNLABELLED To study the regulation of cell pH by ambient pH, carbon dioxide tension (PCO2), and bicarbonate (HCO3), cell pH was measured in the isolated, in vitro microperfused rabbit proximal convoluted tubule using the fluorescent dye (2',7')-bis-(carboxyethyl)-(5,6)-carboxyfluorescein. For the same changes in external pH, changes in [HCO3] and PCO2 affected cell pH similarly ([HCO3]: pHi/pHe...

1. Rabbit caecal segments in situ were used to measure absorption rates of volatile fatty acids (VFA) and inorganic ions from a saline solution comparable in composition to normal caecal fluid. 2. Results confirm the importance of VFA absorption from caecal material found by other workers. 3. Like the mammalian colon, the rabbit caecum conserved large amounts of sodium, chloride and water. Bica...

Groundwater and seepage samples were collected from both the natural and building-modified slopes in the highly urbanized spaces of the Mid-Levels area, Hong Kong. Groundwater in the natural slopes, although retaining some signatures from rainwater, is enriched in major cations such as Na, K, Ca and Mg and some anions such as HCO3 and SO4. Clearly, water-rock interactions, such as weathering of...

relationships between soil factors and vegetation types in playa of damghan was investigated. six vegetationtypes including artemisia.sieberi, arundo. sp, artemisia.sieberi-peganum.harmala, alhagi.cammelerom,artemisia.sieberi-petropyron.sp, tamarix.passerinoides-halocnemum strobilaceum. one bare land was recognized inthe study area and the research was conducted within mentioned types. canopy p...

Our laboratory has previously shown that mice lacking neuronal nitric oxide synthase (nNOS) are defective in fluid absorption (J(v)) and HCO absorption (J(HCO3)) in the proximal tubule and develop metabolic acidosis. The present study examined the transport of fluid and HCO in the proximal tubule and acid-base status in mice lacking two other isoforms of NOS, inducible NOS (iNOS) and endothelia...

Salinization of groundwater in semiarid regions, as a limiting factor of use, has a strategic importance. In this study, the sources of salinity, chemistry and Quality of groundwater in Robat – Khorramabad plain have been identified using geochemical methods. Using data analysis, the concentration of cations and anions are recognized as Ca2+>Na+ >Mg2+>K+ and HCO3-> Cl-> SO42+> NO3-> F-. High co...