We have determined the topology of the Escherichia coli inner membrane protein YrbG, a putative Na(+)/Ca(2+) exchanger with homology to a family of eukaryotic ion exchangers. Our results show that the two homologous halves of YrbG both have five transmembrane segments but opposite membrane orientations. This has implications for our understanding of the function of Na(+)/Ca(2+) exchangers and p...

Intracellular pH is maintained by a dynamic equilibrium balancing the opposing forces of proton loading and proton extrusion. By providing an efflux pathway for base, anion exchangers constitute a key component of the plasma membrane proton-loading machinery. The data in this paper identify a histidine-rich sequence within the cytoplasmic domain of the nonerythroid anion exchanger, AE2, that se...

This review will briefly summarize current knowledge on the basolateral ammonia transport mechanisms in the thick ascending limb (TAL) of the loop of Henle. This segment transports ammonia against a concentration gradient and is responsible for the accumulation of ammonia in the medullary interstitium, which, in turn, favors ammonia secretion across the collecting duct. Experimental data indica...

introduction: iranian scorpion species are classified in buthidae and scorpionidae with 16 genera and 25 species. in iran, similar to other parts of the world, there are a few known species of scorpions responsible for severe envenoming. mesobuthus eupeus is the most common species in iran. its venom contains several toxin fractions which can affect the ion channel. in this study purification, ...

Phosalone, malathion and diazinon were analyzed in corn oil using solid phase extraction (SPE)with lanthanum silicate as a new solid sorbent followed by gas chromatography with nitrogenphosphorus detection (GC-NPD). The efficiency of different eluents (methanol, dichloromethane,ethyl acetate, dichloromethane — ethyl acetate (1:1) and ethyl acetate — methanol (1:1)) werecompared for elution of o...

Emerging evidence suggests that ventricular electrical remodeling (VER) is triggered by regional myocardial strain via mechanoelectrical feedback mechanisms; however, the ionic mechanisms underlying strain-induced VER are poorly understood. To determine its ionic basis, VER induced by altered electrical activation in dogs undergoing left ventricular pacing (n = 6) were compared with unpaced con...

Loss of the lysosomal ClC-7/Ostm1 2Cl /H exchanger causes lysosomal storage disease and osteopetrosis in humans and additionally changes fur colour in mice. Its conversion into a Cl conductance in Clcn7 mice entails similarly severe lysosomal storage, but less severe osteopetrosis and no change in fur colour. To elucidate the basis for these phenotypical differences, we generated Clcn7 mice exp...

An iodide-miconazole ion-paired complex was used as a suitable ion-exchanger for the preparation of a plasticized-PVC membrane electrode. Among different solvent mediators tested, dioctylsebacate exhibited the proper response characteristics, including Nernstian slope of the calibration curve, fast response time and good reproducibility of the emf values. The electrode exhibits a Nernstian slop...

Poly(o-anisidine) molybdophosphate was expediently obtained by sol-gel mixing of Poly(o-anisidine) into the inorganic matrices of molybdophosphate, which was allowed to react with silver nitrate to the formation of poly(o-anisidine) molybdophosphate embedded silver nano composite. The composite was characterized by Fourier Transform Infrared Spectroscopy, X-ray powder diffraction, UV-Vis Spectr...

Bull sharks, Carcharhinus leucas, are one of only a few species of elasmobranchs that live in both marine and freshwater environments. Osmoregulation in euryhaline elasmobranchs is achieved through the control and integration of various organs (kidney, rectal gland and liver) in response to changes in environmental salinity. However, little is known regarding the mechanisms of ion transport in ...