(1) The operon was found to have two functional regions, the promoter-proximal region encoding resistance to arsenite and antimonate and the promoter-distal region encoding arsenate resistance.
(2) At the same time, arsenate stabilizes the delta psi value, but blocks K+ uptake.
(3) Because of the analogous results with arsenate and sulfate, it is suggested that arsenate, like sulfate, may enhance the carcinogenicity of other carcinogens.
(4) The levels of arsenobetaine, which occurs naturally in these fish, did not appear to be affected by the oral dosing with sodium arsenate.
(5) Experiments with both types of cells showed a direct correlation between the arsenate taken up and the amount of As-lipid complex formed.
(6) Pretreatment of the cells with respiratory chain poisons or uncouplers, except for arsenate, inhibited transport up to 95%.
(7) In the presence of phosphate, arsenate uptake is inhibited while in the presence of arsenate, phosphate uptake is only slightly inhibited.
(8) The resistance pattern included arsenate, arsenite, and antimonate ions.
(9) First-time measurements of the potentially toxic inorganic species of arsenic (arsenite and arsenate) have been obtained in fine (less than 2.5 microns AD) and coarse (greater than 2.5 microns AD) atmospheric particles in the Los Angeles area.
(10) The effects of the metabolic inhibitors, arsenate (1,10 mM), iodoacetate (1 mM), alpha-cyano-4-hydroxycinnamate (alpha C4HC: 0.05, 0.15, 0.5 mM), malonate (10 mM) and 2,4-dinitrophenol (10 microM) on granule cell evoked activity and levels of energy metabolites of superfused hippocampal slices were investigated.
(11) Hamster dams were exposed to teratogenic doses of arsenate by means of osmotic minipumps implanted on the morning of Day 6 of the gestation period.
(12) These results suggest that, in the presence of MgADP, vanadate or arsenate, and 3-P-glycerate, the enzyme catalyzed the formation of multiple structurally distinguishable complexes that are stable on the enzyme and labile off the enzyme.
(13) Post mortem reduction of arsenate to arsenite was found to occur rapidly in fish tissue.
(14) The inhibition constants for arsenate and for glycerol phosphate with the mutant enzyme are similar to those with the wild-type isomerase, but the substrate analogues 2-phosphoglycolate and phosphoglycolohydroxamate bind 8- and 35-fold, respectively, more weakly to the mutant isomerase.
(15) Arsenate seems to bind with similar affinity, but with distinctly less protective activity (maximum of 16%).
(16) Inactivation of the high-affinity component evidently requires the utilization of a fermentable substrate by the cells, since inactivation did not occur during carbon starvation, when a fermentable sugar was added to starved cells, inactivation began, when the fermentation inhibitors iodoacetate or arsenate were added in addition to sugars, the inactivation was prevented, when a non-fermentable substrate was added instead of sugars, inactivation was also prevented.
(17) A delay in the rise to the maximum rate of 86Rb release upon stimulation with arsenate is shown to be due to the time required for arsenylation, and from an analysis of the rise and fall of the rate of 86Rb release the rate constants for arsenylation and dearsenylation at pH 7.2 can be estimated; the decay in the rate of 86Rb release when arsenate or phosphate is removed from the solution provides a second method for determination of the dearsenylation rate.
(18) We determined the concentration and chemical status of arsenic in the placentas of hamsters following continuous exposure via the osmotic minipump to minimally and frankly teratogenic doses of arsenate.
(19) The developmental origin of arsenate-induced renal agenesis was investigated.
(20) Cell swelling induced by tetanolysin was much lower with energy-depleted M. gallisepticum cells, with arsenate-treated cells, or when the membrane potential (delta psi) was collapsed by valinomycin (10 microM) plus KCl (100 mM).