In mammals, copper (Cu) absorption occurs mostly in the small intestine, and some of the Cu transporters involved in its uptake have been characterised. In fish, however, the regions of the gut involved in Cu absorption and the membrane transport mechanisms responsible for gastrointestinal Cu uptake are unknown. Everted gut sacs and isolated perfused intestine of Clarias gariepinus were used to...

Hypotonic exposure provokes the mobilization of arachidonic acid, production of ROS, and a transient increase in taurine release in Ehrlich Lettre cells. The taurine release is potentiated by H(2)O(2) and the tyrosine phosphatase inhibitor vanadate and reduced by the phospholipase A(2) (PLA(2)) inhibitors bromoenol lactone (BEL) and manoalide, the 5-lipoxygenase (5-LO) inhibitor ETH-615139, the...

We have shown that myosin light chain phosphorylation inhibits fiber shortening velocity at high temperatures, 30 degrees C, in the presence of the phosphate analog vanadate. Vanadate inhibits tension by reversing the transition to force-generating states, thus mimicking a prepower stroke state. We have previously shown that at low temperatures vanadate also inhibits velocity, but at high tempe...

H+-pumping ATPases were detected in nicrosomal vesicles of oat (Avena sativa L. var Lang) roots using 114Clmethylamine distribution or quinacrine fluorescent quenching. Methylamine (MeA) accumulation into vesicles and quinacrine quench were specifically dependent on Mg,ATP. Both activities reflected formation of a proton gradient (ApH) (acid inside) as carbonyl cyanide m-chlorophenylhydrazone, ...

Abstract Organic esters of phosphoric acid and other organophosphorous compounds are enzymatically hydrolyzed during wastewater treatment by microbial phosphoesterases, especially phosphomonoesterase (phosphatase). For physiological reasons, the enzyme is inhibited its main inorganic reaction product, ortho-phosphate. It known that oxyanions transition metals, resembling molecular topology orth...

Quasi-binary phosphate-vanadate glasses have been studied by both IR spectroscopy and a novel method of molecular dynamics with non-constant force field. This is used for the self-assembly structural models glasses. The obtained glass network structure are analyzed quantitatively using element distribution number R–O–R bonds (R phosphorous or vanadium) 4-, 6-, 8-membered cycles. bends on concen...

Friend murine erythroleukemia cells underwent apparently normal erythropoiesis when treated with dimethyl sulfoxide. One of the earliest events associated with this induction was a decrease in ouabain sensitive 86Rb+ uptake, an assay of the plasma membrane Na, K(ATPase). Ammonium vanadate (10/~M) blocked differentiation of these cells without affecting cell viability. Vanadium was taken up by F...

For the condensation of anions such as phosphate and ADP to form ATP and water, nature employs sophisticated supramolecular systems to overcome coulomb repulsion and activation barriers. For an attempt to create a simple, analogous chemical system, the dimerization of vanadate is probably the simplest model. We have investigated Zn-benzylcyclene which favors the dimerization thermodynamically a...

Measurements were made of the rigor stiffness of impaled bull sperm flagella. Vanadate-free ATP was found to have a stronger plasticizing action than vanadate-contaminated ATP. Trace amounts of Mg2+ were found to be necessary to relieve the rigor condition by ATP. During the injection of negative electric current into the sperm head, the flagella stiffened, presumably by depletion of Mg2+ from ...