The intra-islet insulin hypothesis proposes that the decrement in beta-cell insulin secretion during hypoglycemia provides an activation signal for alpha-cells to release glucagon. A more recent hypothesis proposes that zinc atoms suppress glucagon secretion via their ability to open alpha-cell ATP-sensitive K(+) channels. Since insulin binds zinc, and zinc is co-secreted with insulin, we teste...

The cytotoxic effects of excessive zinc is well documented but its effect on cytodifferentiation appears relatively unknown. We show here that chronic administration (25 days) of zinc chloride in C57/6J mice (11 to 56 micrograms/g body weight, 5 times per week), which was lower than the in vitro cytotoxic level, caused a loss of long coarse hairs, which were replaced by short fine (vello) hairs...

[equation: see text] An efficient one-pot route to unsymmetrical diorganyl selenides has been developed by ruthenium(III) chloride catalyzed reactions of dibenzyl or diphenyl diselenides with alkyl halides in the presence of zinc. Organic iodides, bromides, and activated chlorides underwent the reactions efficiently. Unreactive organic chlorides also underwent the same type of selenation with s...

Reductive S-S bond cleavage of a disulfide precursor obtained from a pyridine-catalyzed Peterson-type reaction starting from camphorpyrazole , thionyl chloride and 2-methyl-2-(methyldithio)propionaldehyde yields 2,2'-bis(camphorpyrazol-1-yl)-2-methylpropane-2-thiol (HSiprbpm3cam, ); the first zinc complexes bearing this ligand exhibit kappa3 coordination of the ligand.

The effects of the heavy-metal ions Cd2+ and Zn2+ on the homoeostasis of intracellular free Ca2+ in E367 neuroblastoma cells were examined using 19F-NMR spectroscopy with the fluorinated chelator probe 1,2-bis-(2-amino-5-fluorophenoxy)ethane-N,N,N', N'-tetra-acetic acid (5F-BAPTA). First, the technique was used to quantify the uptake and intracellular free concentrations of the heavy metals aft...

The effects of foods and chemicals related to food hygiene on degranulation were evaluated using a method for assaying the enzyme activity of beta-hexosaminidase as an index of chemical mediator release from RBL-2H3 cells in vitro. Using a previously developed assay system, we had found a large number of inhibitors and promoters of degranulation of RBL-2H3 cells. In the present study, we examin...

High prevalence of zinc deficiency stemming frommalnutrition, gastrointestinal diseases and low dietary intake accounts for detection of zinc in plasma being a frequently requested clinical pathology assay. Serum and plasma zinc determination by graphite furnace atomic absorption spectrometry (GFAAS) has previously been hampered by significant interfering species and intolerance to high pyrolys...

This work was directed to evaluate immunoexpression of markers for apoptosis, resistance to apoptosis, and cell proliferation, as well as estimates of nuclear size in ventral prostate of rats treated with cadmium chloride and cadmium+zinc chloride because a possible protective effect of zinc has been postulated. The following variables were studied: volume fraction (VF) of Bcl-2 immunostaining,...