The 86Rb efflux by high K+ was measured simultaneously during the mechanical responses in pig duodenal circular muscle using a superfusion technique. A slightly higher K+ (17.7-23.6 mM) simultaneously induced tetrodotoxin (TTX)-sensitive relaxation and 86Rb efflux. Much higher K+ (47.2-143.4 mM) contracted and also increased the 86Rb efflux markedly, but the extent of TTX-sensitive efflux remai...

[1] Soil surface CO2 efflux is an important component of the carbon cycle in terrestrial ecosystems. However, our understanding of mechanistic controls of soil CO2 production and transport is greatly limited. Amultilayer process-based soil CO2 effluxmodel (PATCIS) wasused to evaluate soilCO2production and transport in theDukeForest.CO2production in the soil is the sum of root respiration and so...

Multidrug resistance-associated protein (MRP) isoforms 1 through 6 mRNA are expressed in the human intestine and Caco-2 cells. In Caco-2 cells, the rank order for mRNA expression was MRP2 > or = MRP6 > MRP4 > or = MRP3 > MRP1 = MRP5. The functional expression of MRP-like activity was quantified as the efflux of the fluorescent probe calcein from confluent, polarized monolayers of Caco-2 cells. ...

The balance between photosynthesis and plant respiration in tropical forests may substantially affect the global carbon cycle. Woody tissue CO2 efflux is a major component of total plant respiration, but estimates of ecosystem-scale rates are uncertain because of poor sampling in the upper canopy and across landscapes. To overcome these problems, we used a portable scaffolding tower to measure ...

The Bacillus cereus group of bacteria includes seven closely related species, three of which, B. anthracis, B. cereus and B. thuringiensis, are pathogens of humans, animals and/or insects. Preliminary investigations into the transport capabilities of different bacterial lineages suggested that genes encoding putative efflux systems were unusually abundant in the B. cereus group compared to othe...

Numerous studies show efflux as a universal bacterial mechanism contributing to antibiotic resistance and also that the activity of the antibiotics subject to efflux can be enhanced by the combined use of efflux inhibitors. Nevertheless, the contribution of efflux to the overall drug resistance levels of clinical isolates of Mycobacterium tuberculosis is poorly understood and still is ignored b...

The Ruthenium Red-insensitive efflux of Ca2+ from previously loaded rat liver mitochondria was studied as a function of the added Na+ concentration and ADP present. Stimulation of Ca2+ efflux is sigmoidally dependent on the Na+ concentration; maximal stimulation of efflux was observed with 12--15 mM-NaCl. Na+-stimulated Ca2+ efflux from liver mitochondria is about one-tenth that from cardiac mi...

Metabolism and sinusoidal/canalicular efflux of mycophenolic acid (MPA) was investigated using sandwich-cultured hepatocytes (SCHs). After applying MPA to SCHs from humans, wild-type rats, and multidrug resistance-associated protein (Mrp) 2-deficient rats, the MPA metabolites 7-O-glucuronide (MPAG) and acyl glucuronide (AcMPAG) were detected in the intracellular compartment of the SCHs. Sinusoi...

The purpose of this study was to investigate the factors controlling membrane permeability to potassium of smooth muscle cells from rat aorta stimulated by depolarization. The increase 42K+ efflux (change in the rate constant) induced by depolarization (application of high concentrations of potassium chloride) was inhibited significantly by the calcium antagonists diltiazem and nisoldipine. Par...