Thin strips of frog ventricle were isolated and bathed for 15 min in a solution containing 140 mM KCl, 5 mM Na(2)ATP, 3 mM EDTA, and 10 mM Tris buffer at pH 7.0. The muscle was then exposed to contracture solutions containing 140 mM KCl, 5 mM Na(2)ATP, 1 mM MgCl(2), 10 mM Tris, 3 mM EGTA, and CaCl(2) in amounts to produce concentrations of free calcium from 10(-4.8)M to 10(-9)M. The muscles dev...

Ca efflux in dialyzed squid axons was measured with 45Ca as a function of internal ionized Ca in the range 0.005-10 muM. Internal Ca stores were depleted by treatment with CN and dialysis with media free of high energy compounds. The [Ca]iota was stabilized with millimolar concentrations of EDTA, EGTA, or DTPA. Nonspecific leak of chelated Ca was measured with [14C]-EDTA and found to be 0.02 pm...

Evidence was found for a Na(+)/H(+) antiport in tonoplast vesicles isolated from barley (Hordeum vulgare L. cv California Mariout 72) roots. The activity of the antiport was observed only in membranes from roots that were grown in NaCl. Measurements of acridine orange fluorescence were used to estimate relative proton influx and efflux from the vesicles. Addition of MgATP to vesicles from a ton...

We evaluated the inducibility of nitrate-dependent Fe(II)-EDTA oxidation (NDFO) in non-growth, chloramphenicol-amended, resting-cell suspensions of Dechloromonas sp. strain UWNR4 and Acidovorax sp. strain 2AN. Cells previously incubated with Fe(II)-EDTA oxidized ca. 6-fold more Fe(II)-EDTA than cells previously incubated with Fe(III)-EDTA. This is the first report of induction of NDFO by Fe(II).

The effects of Ca, K, Na, calcite, and EDT A on Pb immobilization by hydroxyapatite [CaIO(P04)6(OHh; HAl were investigated. The stability of hydroxy pyromorphite [PbIO(P04MOHh; HPJ (a reaction product of HA with Pb) and the effectiveness of using HA to immobilize Pb in Pb-contaminated soils also were examined. Neither Na nor K affected Pb immobilization. Aqueous Ca and calcite slightly inhibite...

The infrared and Raman spectra of Na[FeEDTA(H(2)O)]x2H(2)O and Na(4)[(FeEDTA)(2)O]x3H(2)O (EDTA=tetra anion of ethylenediaminetetraacetic acid), two complexes proposed as adequate for iron supplementation, were recorded and analyzed in relation to its structural peculiarities. Some comparisons between the recorded spectra are also presented, and the characteristics of the carboxylate motions as...

The trior tetrasodium salt of ethylenediaminetetraacetic acid (EDTA or Na EDTA) is a strong chelating agent for heavy metals and the alkaline earth metals, calcium and magnesium. By this action the activity of enzymes which are known to be influenced by calcium or magnesium is altered by the addition of EDTA; e.g., muscle adenylate kinase, which is accelerated by magnesium, is completely inacti...

4 2 containing FeSO and Na EDTA. EDTA could be replaced by citric acid. In this in vitro system 4hydroxybenzoic acid is hydroxylated to 3,4-dihydroxybenzoic acid (protocatechuic acid) and decarboxylated to hydroquinone. In an analogous reaction 2-hydroxybenzoic acid (salicylic acid) is hydroxylated to 2,3-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid (gentisic acid) and decarboxylated to ...