The effect of a-mercapto-β-(2-furyl) acrylic acid (MFA, 200 mg/kg, oral) administered 30 min or 24 h post cadmium (1 mg/kg, i.p.) exposure on cadmium toxicity, was investigated in rats. The Cd induced hepatic metallo...The effect of a-mercapto-β-(2-furyl) acrylic acid (MFA, 200 mg/kg, oral) administered 30 min or 24 h post cadmium (1 mg/kg, i.p.) exposure on cadmium toxicity, was investigated in rats. The Cd induced hepatic metallothionein was reduced by MFA treatment parallel to the depletion of hepatic Cd. However, in renal tissue,MFA caused only redistribution of metal from the paniculate to the soluble fraction. Hepatic and renal Zn and renal Cu were significantly increased on Cd exposure. MFA therapy, however, lowered the hepatic Zn and increased the renal Cu levels. The action of MFA appears to be via metal chelation rather than by MT induction.展开更多
Objective To synthesize some new a-mercapto-β-substituted aryl acrylic acids, characterize them and investigate their in vitro cadmium chelating ability. Methods Six α-mercapto-β-substituted aryl acrylic acids were...Objective To synthesize some new a-mercapto-β-substituted aryl acrylic acids, characterize them and investigate their in vitro cadmium chelating ability. Methods Six α-mercapto-β-substituted aryl acrylic acids were prepared by the alkaline hydrolysis of 5- (aryl methylene) rhodanines, obtained from the condensation of substituted aldehydes and rhodanine following the reported procedure. The new compounds were characterized by elemental analysis, infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy. The liver and kidney from cadmium chloride pre-administered rats were homogenized and their nuclear mitochondrial fraction (NMF) and supernatant cytosol fraction (SCF) were separated. A measured volume of each fraction was dialyzed separately using 'dialysis sack' against buffered-KCl medium containing a compound in the final concentration of 1×10-3 mol/L for 3 h at 37℃. The whole content of 'sack' was subjected to cadmium estimation following digestion with cone. Nitric acid was detected using flame atomic absorption spectrometer. Results The in vitro screening showed that α-mercapto-β-(p-methoxyphenyl) acrylic acid (compound 2) andα-mercapto-β-(m-methoxy, p-hydroxyphenyl) acrylic acid (compound 4) were more effective than α-mercapto-β-thienyl acrylic acid (compound 1) and a-mercapto-β-(p-dimethylaminophenyl) acrylic acid (compound 3) in mobilizing cadmium as their dialyzable chelates. The presence of a methoxy group on the phenyl moiety (compounds 2 and 4) increases the metal chelating ability of mercapto acrylic acids. Conclusions Compounds 2 and 4 seem to have accessibility to the cellular system and capability of chelating-out the intracellularly bound cadmium.展开更多
The effectiveness of certain substituted dithiocarbamates in mobilizing lead from preexposed rats was investigated.The animals received 10mg Pb/kg/day, intragastrically.for 8 weeks and were treated thereafter with 400...The effectiveness of certain substituted dithiocarbamates in mobilizing lead from preexposed rats was investigated.The animals received 10mg Pb/kg/day, intragastrically.for 8 weeks and were treated thereafter with 400μmol/kg, intraperitoneally.of morpholine dithiocarbamate, tetraammonium ethylenediamine diacetic acid dithiocarbamate (EDDTC), ammonium diethanolamine dithiocarbamate (ADDTC), sodium diethyldithiocarbamate.N-benzyl-D-glucamine dithiocarbamate (NBGDTC), or dimercaptosuccinic acid, daily for 5 days.All the chelating agents were effective in lowering the hepatic and renal burden of Pb.ADDTC.EDDTC, and NBGDTC were also able to lower the long bone Pb content.The lowering of Pb burden had no relationship to restoration of Pb-induced hematopoietic alterations.The relatively lower lipophilicity of substituted dithiocarbamates, owing to the presence of hydrophilic groups, seems to be advantageous in preventing passage of metal chelale into the brain.None of the substituted dithiocarbamates caused excessive excretion of urinary Cu and Zn.ADDTC and EDDTC appear to be promising in the management of Pb poisoning. 1990 Academic Press.Inc.展开更多
文摘The effect of a-mercapto-β-(2-furyl) acrylic acid (MFA, 200 mg/kg, oral) administered 30 min or 24 h post cadmium (1 mg/kg, i.p.) exposure on cadmium toxicity, was investigated in rats. The Cd induced hepatic metallothionein was reduced by MFA treatment parallel to the depletion of hepatic Cd. However, in renal tissue,MFA caused only redistribution of metal from the paniculate to the soluble fraction. Hepatic and renal Zn and renal Cu were significantly increased on Cd exposure. MFA therapy, however, lowered the hepatic Zn and increased the renal Cu levels. The action of MFA appears to be via metal chelation rather than by MT induction.
基金This research was supported by the Council of Science and Technology, U. P state government.
文摘Objective To synthesize some new a-mercapto-β-substituted aryl acrylic acids, characterize them and investigate their in vitro cadmium chelating ability. Methods Six α-mercapto-β-substituted aryl acrylic acids were prepared by the alkaline hydrolysis of 5- (aryl methylene) rhodanines, obtained from the condensation of substituted aldehydes and rhodanine following the reported procedure. The new compounds were characterized by elemental analysis, infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy. The liver and kidney from cadmium chloride pre-administered rats were homogenized and their nuclear mitochondrial fraction (NMF) and supernatant cytosol fraction (SCF) were separated. A measured volume of each fraction was dialyzed separately using 'dialysis sack' against buffered-KCl medium containing a compound in the final concentration of 1×10-3 mol/L for 3 h at 37℃. The whole content of 'sack' was subjected to cadmium estimation following digestion with cone. Nitric acid was detected using flame atomic absorption spectrometer. Results The in vitro screening showed that α-mercapto-β-(p-methoxyphenyl) acrylic acid (compound 2) andα-mercapto-β-(m-methoxy, p-hydroxyphenyl) acrylic acid (compound 4) were more effective than α-mercapto-β-thienyl acrylic acid (compound 1) and a-mercapto-β-(p-dimethylaminophenyl) acrylic acid (compound 3) in mobilizing cadmium as their dialyzable chelates. The presence of a methoxy group on the phenyl moiety (compounds 2 and 4) increases the metal chelating ability of mercapto acrylic acids. Conclusions Compounds 2 and 4 seem to have accessibility to the cellular system and capability of chelating-out the intracellularly bound cadmium.
文摘The effectiveness of certain substituted dithiocarbamates in mobilizing lead from preexposed rats was investigated.The animals received 10mg Pb/kg/day, intragastrically.for 8 weeks and were treated thereafter with 400μmol/kg, intraperitoneally.of morpholine dithiocarbamate, tetraammonium ethylenediamine diacetic acid dithiocarbamate (EDDTC), ammonium diethanolamine dithiocarbamate (ADDTC), sodium diethyldithiocarbamate.N-benzyl-D-glucamine dithiocarbamate (NBGDTC), or dimercaptosuccinic acid, daily for 5 days.All the chelating agents were effective in lowering the hepatic and renal burden of Pb.ADDTC.EDDTC, and NBGDTC were also able to lower the long bone Pb content.The lowering of Pb burden had no relationship to restoration of Pb-induced hematopoietic alterations.The relatively lower lipophilicity of substituted dithiocarbamates, owing to the presence of hydrophilic groups, seems to be advantageous in preventing passage of metal chelale into the brain.None of the substituted dithiocarbamates caused excessive excretion of urinary Cu and Zn.ADDTC and EDDTC appear to be promising in the management of Pb poisoning. 1990 Academic Press.Inc.
