Biomaterial Database

The insulin-like effects of low molecular weight thiols: role of trace metal contamination of commercial thiols. 1980

J M May

During the investigation of insulin-like effects of low molecular weight thiols in rat adipocytes it was found that thiol autoxidation to H2O2 occurred even in the absence of albumin and cells. Since chromatography of the thiols on a chelating ion exchange resin prevented H2O2 formation, it is likely that trace metal contaminations of the thiol preparations catalyzed thiol autoxidation in oxygenated solutions. Incubation of rat adipocytes with 1 mM dithioerythritol and low concentrations of dialyzed albumin stimulated 2-deoxyglucose transport, glucose metabolism to CO2 and lipids, and formate resin or in most instances incubation with EDTA or catalase prevented these effects. The antilipolytic effect of dithioerythritol was also abolished by catalase. The insulin-like effects of thiols therefore appear to be solely mediated by H2O2 generated during thiol autoxidation catalyzed by trace metal contaminants either of albumin or of the commercial thiol preparation itself.

UI	MeSH Term	Description	Entries
D007328	Insulin	A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).	Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D008297	Male		Males
D008670	Metals	Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metal
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D002374	Catalase	An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.	Catalase A,Catalase T,Manganese Catalase,Mn Catalase
D004226	Dithioerythritol	A compound that, along with its isomer, Cleland's reagent (DITHIOTHREITOL), is used for the protection of sulfhydryl groups against oxidation to disulfides and for the reduction of disulfides to sulfhydryl groups.	2,3-Dihydroxy-1,4-dithiolbutane,Dithioerythreitol
D004229	Dithiothreitol	A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.	Cleland Reagent,Cleland's Reagent,Sputolysin,Clelands Reagent,Reagent, Cleland,Reagent, Cleland's
D004340	Drug Contamination	The presence of organisms, or any foreign material that makes a drug preparation impure.	Drug Adulteration,Drug Contamination, Chemical,Drug Contamination, Microbial,Drug Contamination, Physical,Drug Impurity,Adulteration, Drug,Chemical Drug Contamination,Chemical Drug Contaminations,Contamination, Chemical Drug,Contamination, Drug,Contamination, Microbial Drug,Contamination, Physical Drug,Contaminations, Chemical Drug,Contaminations, Microbial Drug,Contaminations, Physical Drug,Drug Adulterations,Drug Contaminations,Drug Contaminations, Chemical,Drug Contaminations, Microbial,Drug Contaminations, Physical,Drug Impurities,Impurity, Drug,Microbial Drug Contamination,Microbial Drug Contaminations,Physical Drug Contamination,Physical Drug Contaminations
D005947	Glucose	A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.	Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose