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M D Faiman

Publications and source records attributed to M D Faiman.

9 recordsLinked to original sources
PubMed1992

In vitro and in vivo inhibition of rat liver aldehyde dehydrogenase by S-methyl N,N-diethylthiolcarbamate sulfoxide, a new metabolite of disulfiram.

In summary, these data provide the first evidence that DETC-MeSO is a natural metabolite of disulfiram, and a potent inhibitor of rat liver mitochondrial low Km ALDH both in vitro and in vivo. It is therefore proposed that, based upon evidence to date, DETC-MeSO appears to be the chemical species to which disulfiram must be bioactivated, and is the metabolite most likely responsible for disulfiram's inhibition of rat liver mitochondrial low Km ALDH in vivo. Characterization of the properties of DETC-MeSO as the metabolite responsible for disulfiram's action as an ALDH inhibitor is presently in the process of being completed.

Aldehyde Dehydrogenase↗
PubMed1991

Disulfiram metabolism as a requirement for the inhibition of rat liver mitochondrial low Km aldehyde dehydrogenase.

In humans and animals, disulfiram produces a disulfiram-ethanol reaction after an ethanol challenge, the basis of which is the inhibition of liver aldehyde dehydrogenase (ALDH). Disulfiram and the metabolites diethyldithiocarbamate (DDTC), diethyldithiocarbamate-methyl ester (DDTC-Me), and S-methyl-N,N-diethylthiolcarbamate (DETC-Me) were studied in order to determine the role of bioactivation in disulfiram's action as an inhibitor of rat liver mitochondrial low Km ALDH (RLM low Km ALDH). In in vitro studies, disulfiram and DDTC (0.01 to 2.0 mM) both inhibited RLM low Km ALDH in a concentration-dependent manner. The addition of rat liver microsomes to the mitochondrial incubation did not further increase disulfiram-induced RLM low Km ALDH inhibition. However, DDTC-induced RLM low Km ALDH inhibition was increased further, but only at DDTC concentrations less than 0.05 mM. DDTC-Me and DETC-Me (2.0 mM) similarly exhibited an increased RLM low Km ALDH inhibition after the addition of liver microsomes. In in vivo studies, disulfiram (75 mg/kg), DDTC (114 mg/kg), DDTC-Me (41.2 mg/kg) or DETC-Me (18.6 mg/kg) administered i.p. to female rats inhibited RLM low Km ALDH. Inhibition of drug metabolism by pretreatment of rats with the cytochrome P450 inhibitor N-octylimidazole (NOI) (20 mg/kg, i.p.) prior to either disulfiram, DDTC, DDTC-Me or DETC-Me administration blocked the inhibition of RLM low Km ALDH. The in vitro and in vivo data support the conclusion that bioactivation of disulfiram to a reactive chemical species is required for RLM low Km ALDH inhibition and a disulfiram-ethanol reaction.

Aldehyde Dehydrogenase↗
PubMed1978

Cerebral oxidized and reduced nicotinamide-adenine dinucleotide phosphate and glucose 6-phosphate dehydrogenase in mice during exposure to high oxygen pressure.

NADP+, NADPH and glucose 6-phosphate dehydrogenase were determined in the cerebral cortex of mice exposed to high O2 pressure for 0, 8 and 16 min. These time intervals corresponded to 0, 50 and 100% of the CT50 (the time taken for 50% of the mice to convulse). Cerebral NADP+, NADPH and glucose 6-phosphate dehydrogenase also were determined in O2-exposed mice exhibiting hyperactivity, convulsions, and in mice killed 10s after convulsions. Similar increases in cortical NADP+ and decreases in NADPH were found in mice exposed to 610kPa (6 atm.) of 100% O2 for 0, 50 and 100% of the CT50, during hyperactivity, onset of seizure and 10s after convulsions. The NADP+/NADPH ratio increased approx. 25% at 0% of the CT50, and remained at this increased value at all O2-exposure periods including the hyperactive state, onset of seizure and 10s after convulsions. Identical changes in cerebral NADP+ , NADPH and the NADP+/NADPH ratio were found in mice exposed for 16min to 100% O2 at 100, 350 or 610kPa. No change in cerebral glucose 6-phosphate dehydrogenase was found in mice exposed to 610kPa of 100% O2 during the various stages of O2 toxicity. Only in the 10s post-convulsive group was a statistically significant decrease in glucose 6-phosphate dehydrogenase observed. Disulfiram [bis(diethylthiocarbamoyl) disulphide], an effective O2-protective agent, did not prevent the O2-induced increase in cerebral NADP+ and the NADP+/NADPH ratio, or decrease in NADPH.

Animals↗
PubMed1978

Radioactive and nonradioactive methods for the in vivo determination of disulfiram, diethyldithiocarbamate, and diethyldithiocarbamate-methyl ester.

Although disulfiram (tetraethylthiuram disulfide; DSF) has been used in the treatment of alcoholism for almost a quarter of a century, little is known about its in vivo metabolism. One reason for this is that few analytical methods are available that can determine DSF and its various metabolites in biologic fluids and tissues. This article describes two simple procedures for the determination of these substances.

Blood Chemical Analysis↗
PubMed1978

Cerebral and blood glucose in central oxygen poisoning.

Studies were carried out to determine the effect of high oxygen pressure (OHP) on brain and blood glucose. OHP increased cerebral glucose in mice killed at various stages of oxygen toxicity. This included times which corresponded to 75% and 100% of the CT50, the hyperactive state, and at seizure onset. Blood glucose also was increased but only when mice were exposed to oxygen for times which produced stress-related responses. These were at 100% of the CT50,during hyperactivity, and at the onset of seizures. The increase in cerebral glucose was due to the increased oxygen pressure and not to the pressure per se. Adrenalectomy blocked the oxygen-induced increase in blood glucose but not in cerebral glucose. Disulfiram, an effective oxygen protectant, markedly increased both brain and blood glucose.

Animals↗
PubMed1977

A rapid and simple radioactive method for the determination of disulfiram and its metabolites from a single sample of biological fluid or tissue.

An analytical method is described for the determination of radioactive disulfiram, diethyldithiocarbamate, diethyldithiocarbamate-methyl ester, diethyldithiocarbamate-glucuronide, inorganic sulfate, and a protein bound S35 fraction from a single sample of either plasma, urine or tissue. The procedure is based upon quantitative stepwise extraction or precipitation of the individual compounds, and is both specific and precise. The applicability of the methods developed for the determination of S35 disulfiram and its S35 metabolites in plasma and urine from a dog given S35 disulfiram i.v., and in mouse brain from mice given S35 disulfiram i.p. are illustrated.

Animals↗