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Biomedical subjects

K G Römer

Publications and source records attributed to K G Römer.

7 recordsLinked to original sources
PubMed1985

Ethanol-induced accumulation of ethylene glycol monoalkyl ethers in rats.

In adult female SPF Sprague-Dawley rats, exposed for 2 hours to 2-methoxy-ethanol (ME, 1600 ppm), 1-acetoxy-2-methoxy-ethane (AME, 800 ppm), 2-ethoxy-ethanol (EE, 420 ppm), or 1-acetoxy-2-ethoxy-ethane (AEE, 170 ppm) the blood level of ME (after ME or AME) or EE (after EE or AEE) was considerably increased after pretreatment with ethanol (20 mmol/kg b.w. i.p.). (ME and EE are metabolites of AME and AEE, respectively.) After i.p. co-administration of ME (10 mmol/kg), EE (10 mmol/kg) or butoxy-ethanol (BE, 2.5 mmol/kg) with ethanol (20 mmol/kg) the blood level of ME, EE, and BE remained nearly constant as long as ethanol levels in blood were above 3 mmol/l. Repeated i.p. dosing (5 times one injection per hour) with EE (4 mmol/kg) or ME (5 mmol/kg) plus ethanol (8 or 10 mmol/kg) each resulted in an almost complete accumulation of both ether compounds in the blood. Blood levels of ethanol were increased significantly after EE, but only slightly after ME administration. The prolonged retention of ME, EE, or BE is due to an inhibition of the degradation of these compounds following the competition with ethanol at the alcohol dehydrogenase, the common metabolizing enzyme. This study has demonstrated that glycol ether derivatives are extremely accumulated as long as only very low levels of ethanol are present in blood. Therefore, it is concluded that the elimination of the investigated glycol ethers after occupational exposure can be retarded in alcoholized employees causing an increased health risk of these chemicals following the consumption of alcoholic beverages.

Animals↗
PubMed1983

Diminution of ethanol-induced hyperglycaemia in the rat by administration of beta-lactam antibiotics with a tetrazole thiol group.

The acute-onset hyperglycaemia produced by i.p. injection of 2 g of ethanol/kg body weight in adult female SPF Sprague-Dawley rats (200-220 g) was considerably less pronounced when 100 mumol/kg b.w. of one of the following tetrazole thiol-containing beta-lactam antibiotics (BLAs) was given i.p. 3 hours in advance: cephamandole (CMD), moxalactam (MOX), cephoperazone (CPZ) or cephothiam (CTM). An equimolar dose of cephazolin (CEZ), a thiadiazole thiol-containing cephalosporin, did not affect the ethanol-induced hyperglycaemia. Administration of an equimolar oral dose of disulfiram, which has an NCS structure similar to that of the tetrazole thiol-containing BLAs, produced an additional increase of the ethanol-induced hyperglycaemia. The diminution of the ethanol-induced hyperglycaemia by BLAs with a tetrazole thiol group appears to be linked to their NCS structure. It is conceivable that this effect which might be important for human therapy, is causally related to an inhibition of the glycolytic or gluconeogenetic enzyme system.

Animals↗
PubMed1983

Blood acetaldehyde levels in alcohol-dosed rats after treatment with ANIT, ANTU, dithiocarbamate derivatives, or cyanamide.

In adult female Wistar rats, pretreated by gavage with two doses - 16 or 256 mumol/kg - of cyanamide, TMTD (tetramethylthiuram disulfide), TMTM (tetramethylthiuram monosulfide), Ziram or Zineb at 90 min or 18 h before administration of 2 g of ethanol/kg i.p., the blood acetaldehyde levels were significantly increased for 90 - 240 min after ethanol administration (exceptions were noted after exposure to Zineb for 90 min or to low-dosed cyanamide for 18 h). After pretreatment for identical periods with ANTU (N-1-naphthylthiourea) or ANIT (1-naphthylisothiocyanate) at doses extending into the LD50 range, the blood acetaldehyde levels of rats given the same dose of ethanol remained uninfluenced. The increase in blood acetaldehyde recorded after 16 mumol/kg p.o. of TMTM and TMTD remained detectable for up to 48 h. Onset of the cyanamide action occurred already after 45 min. While recognizing that results from animal experiments cannot be transposed without restriction to the human situation, it is concluded that occupational contacts with ANTU or ANIT are not likely to elicit increased blood acetaldehyde levels in man after ingestion of alcohol. The risk of an ethanol intolerance reaction due to a rise in blood acetaldehyde therefore does not appear to be warranted. The present findings indicate, however, that exposure to TMTD, TMTM, Ziram, Zineb or cyanamide is associated with a definite health risk; because of the long persistence of these substances in the body, the risk exists for a long time post-exposure.

1-Naphthylisothiocyanate↗
PubMed1981

The inhibitory action of dithiocarbamates and carbon disulphide on malondialdehyde formation resulting from lipid peroxidation in rat liver microsomes.

The dithiocarbamates (DTCs) disulfiram, thiram, diethyldithiocarbamate and dimethyldithiocarbamate on the equimolar base inhibited to the same extent both the lipid peroxidation (LPO) induced by ascorbic acid (non-enzymatic) and that stimulated by an NADPH-regenerating system with CCl4 admixture (enzymatic). Lipid peroxidation measurements were made in terms of malondialdehyde (MDA) formation in rat liver microsomes, or in the 9000 X g supernatant. The inhibitory action of tetramethylthiuram monosulphide was considerably weaker. Carbon disulphide (CS2) inhibited the enzymatic and non-enzymatic stimulated microsomal LPO by 4 orders less than the DTCs. In parallel with the inhibition of MDA formation, oxidative destruction of microsomal cytochrome P-450 was delayed with increasing concentrations of the DTCs. A well-correlated, non-linear, semi-logarithmic relation was found for the concentration-activity relationship for all DTCs and CS2. As the DTCs inhibited LPO both in heat-denatured and freshly prepared microsomes, it can be deduced that the DTCs intervene in a non-enzymatic oxidation phase of the LPO. The DTC inhibitory action is attributed to a radical-trap mechanism since LPO that has already been initiated was inhibited with the DTCs. However, more inhibitor is required to trap the radicals the later the DTC administration takes place.

Animals↗