background: the mechanism of hypoxic pulmonary vasoconstriction (hpv) is still debatable. it has been proposed that reactive oxygen species (ros) might be involved in hpv. however, there is no special transporter for superoxide anion in the cell membrane and it may release from the cells via anion exchanger. therefore, the aim of this study was to investigate the interaction of ros and anion ex...

Defects in myocyte contraction and relaxation are key features of human heart failure. Sodium/calcium exchanger-mediated contribution to contraction and relaxation were separated from other mechanisms [L-type calcium current, sarco(endo)plasmic reticulum (SR) Ca(2+)-ATPase] based on voltage, temperature, and selective blockers. Rod-shaped left ventricular myocytes were isolated from failed huma...

Affinity-purified antibodies against the C-terminal region of the Na+/H+ exchanger (NHE-1) were used to analyse the carbohydrate moiety of the protein. The Na+/H+ exchanger in human placental brush-border membranes has an apparent molecular mass of 105 kDa. Incubation of intact or detergent-solubilized membranes with glycopeptidase F removed the carbohydrate moiety and increased the apparent mo...

The thermal performance of a heat exchanger is important for the potential application in an integrated solar cell/module and thermoelectric generator (TEG) system. Usually, the thermal performance of a heat exchanger for TEGs is analysed by using 1D heat conduction theory which ignores the detailed phenomena associated with thermo-hydraulics. In this paper, thermal and momentum transports in t...

Intracellular pH regulation in primary cultures of neonatal cardiac myocytes has been characterized. Myocytes were exposed to hyperosmolar solutions to examine the effects on pH regulation by the Na+/H+ exchanger. Exposure to 100 mM NaCl, sorbitol, N-methyl-D-glucamine, or choline chloride all caused significant increases in steady state pHi in myocytes. Omission of extracellular calcium or adm...

The Na(+)/Ca(2+) exchanger participates in Ca(2+) homeostasis in a variety of cells and has a key role in cardiac muscle physiology. We studied in this work the exchanger of amphibian skeletal muscle, using both isolated inside-out transverse tubule vesicles and single muscle fibers. In vesicles, increasing extravesicular (intracellular) Na(+) concentration cooperatively stimulated Ca(2+) efflu...

An analytical model for a condenser with a wetted surface is developed by applying the governing conservations and rate equations and invoking the heat and mass transfer analogy. The heat exchanger is discretized in both the airflow and refrigerant-flow directions for a cross-flow configuration. Axial conduction along the tube walls is neglected and uniform distribution of water is assumed at t...

The widely accepted model to explain the positive inotropic effect of cardiac glycosides invokes altered Na -Ca exchange activity secondary to Na pump inhibition. However, proof of this model is lacking and alternative mechanisms have been proposed. We directly tested the role of the Na -Ca exchanger in the action of the glycoside ouabain using Na -Ca exchanger knockout mice. Ablation of the ex...

This review examines the physiological functions of the Li+-Na+ exchanger and Na+-K+-Cl- cotransport system in human red blood cells. Both transporters are family aggregated and determined mainly by genetic factors; they are present in kidney and vascular cells, where they are regulated by vasoactive substances. To assess the physiological function of these two transporters, we investigated the...

Sodium-dependent Cl(-)/HCO3 (-) exchanger acts as a chloride (Cl(-)) efflux in lymphocytes. Its functional characterization had been described when Cl(-) efflux was measured upon substituting extracellular sodium (Na(+)) by N-methyl-D-glucamine (NMDG). For Na(+) and Cl(-) substitution, we have used D-mannitol or NMDG. Thymocytes of male Wistar rats aged 7-9 weeks were used and intracellular Cl(...