Chelation in Metal Intoxication XXIX: α-Mercapto-β-aryl Acrylic Acids as Antidotes to Mercury (II) Toxicity.

α-Mercapto-β-(2-furyl) acrylic acid (MFA), α-mercapto-β-(phenyl) acrylic acid (MPA), α-mercapto-β-(2-hydroxyphenyl) acrylic acid (MHA), α-mercapto-β-(4-methoxyphenyl) acrylic acid (MMA), β-1,2-phenylene di-α-mercapto acrylic acid (1, 2-PDMA) and β-1, 4-phenylene di-α-mercapto acrylic acid (1, 4-PDMA) enhanced faecal excretion and reduced liver, spleen and blood burden of inorganic mercury when administered (0.5 m mol/kg, in two split doses) 24 hr after Hg (II) (1 mg/kg) in rats. MFA, MPA, MHA and MMA were also effective in lowering renal Hg mainly from the cytosol, without any significant increase in urinary excretion of Hg. The results indicate that all the mono-mercapto acrylic acids including MFA were more effective than di-mercapto acrylic acids and act through the mechanism characteristic of thiol chelators, that is, mobilization of Hg as their complexes, contrary to the reported observation that MFA acts through the induction of metallothionein. [ABSTRACT FROM AUTHOR]