zineb and nabam

Mancozeb is a fungicide of the ethylene bisdithiocarbamate (EBDC) class complexed to the metals manganese and zinc. Nabam is the sodium salt of the EBDC backbone. The purpose of this study was to determine if these EBDC compounds alter essential metal homeostasis and glutathione status in Sprague-Dawley rats. Our findings indicate EBDCs caused accumulation of copper in kidneys, but not liver. EBDC compounds also increased glutathione reductase activity in liver, but not kidneys, whereas only mancozeb increased glutathione peroxidase activity in the liver. Mancozeb and nabam increased total glutathione in liver, but only mancozeb increased total glutathione in the kidney. Neither mancozeb nor nabam altered glutathione ratio in either liver or kidney compared to control. Our data suggest that the EBDC backbone of mancozeb, and not the zinc or manganese moieties, is responsible for changes in glutathione status and alteration of essential metal homeostasis in rat liver and kidney.

Topics: Animals; Ethylenebis(dithiocarbamates); Ethylenes; Fungicides, Industrial; Glutathione; Kidney; Liver; Maneb; Manganese; Metals; Rats; Rats, Sprague-Dawley; Zinc; Zineb

Residues of EBDC (ethylenebisdithiocarbamate) fungicides and ETU (ethylenethiourea; 2-imidazolidinethione) were monitored in beers and wines from different locations. No EBDC residues were detected in any of the samples examined. Concerning the ETU residues, the residue levels higher than the limit of method detection (0.01 ppm) were 22.6% and 7.3% in the commercial beer and wine samples respectively, but the number of samples containing more than 0.1 ppm of ETU was practically negligeable.

Topics: Beer; Chromatography, Gas; Ethylenebis(dithiocarbamates); Ethylenethiourea; Fungicides, Industrial; Gas Chromatography-Mass Spectrometry; Imidazoles; Maneb; Pesticide Residues; Thiocarbamates; Wine; Zineb

In vitro effects of the ethylene bis-dithiocarbamate fungicides, nabam and zineb, on the hepatic microsomal monooxygenases of male rats were examined. Incubation of nabam and zineb with hepatic microsomes, without NADPH, leads to an inhibition of the metabolism of aminopyrine and aniline and to a denaturation of cytochrome P-450 into cytochrome P-420; in addition nabam causes the destruction of cytochrome P-450. Addition of NADPH into the incubation medium increases the inhibition of the monooxygenases, principally the inhibition of the metabolism of aniline induced by nabam. We studied the in vitro effects of three of the chief breakdown products of these fungicides: ethylene bis-isothiocyanate sulfide (EBIS), ethylene thiourea (ETU), and carbon disulfide (CS2). EBIS appears to be the only metabolite affecting directly (without NADPH) the hepatic monooxygenases activity. EBIS accounted partly for nabam-induced inhibition of the hepatic microsomal monooxygenases. The data suggest that the decrease of monooxygenases activity seen on incubation of nabam with hepatic microsomes may be due to the denaturation and destruction of cytochrome P-450 resulting from covalent binding of the compounds with cysteine sulfhydryl groups in cytochrome P-450. Inhibition of monooxygenase activity induced by zineb seems to be due to the reaction with the sulfhydryl groups of cytochrome P-450 and to another mechanism, probably related to its lipophilic character.

Topics: Aminopyrine N-Demethylase; Aniline Hydroxylase; Animals; Cytochrome P-450 Enzyme System; Cytochromes; Enzyme Activation; Ethylenebis(dithiocarbamates); In Vitro Techniques; Male; Microsomes, Liver; NADP; Rats; Rats, Inbred Strains; Thiocarbamates; Zineb

Topics: Aminopyrine; Aniline Compounds; Animals; Biotransformation; Cytochrome P-450 Enzyme System; Ethylenebis(dithiocarbamates); Fungicides, Industrial; Male; Microsomes, Liver; Oxygenases; Rats; Rats, Inbred Strains; Sulfhydryl Compounds; Thiocarbamates; Zineb