An extracorporeal complexing hemodialysis system for the treatment methylmercury poisoning. II. In vivo applications in the dog

An extracorporeal regional complexing hemodialysis procedure is described which has been successfully applied for the enhancement of removal of methylmercury in the dog. The procedure utilizes the extracorporeal addition of cysteine to arterial blood entering a hemodialyzer, forming a large pool of complexed dialyzable methylmercury in plasma. Diffusion of this methylmercury complex across the dialyzer membrane into dialysate accounts for large amounts of methylmercury being removed from the animal. In conjunction with methylmercury removal, the majority of the infused cysteine is also removed resulting in comparatively low systemic doses of cysteine to the animal. At blood flow rates of 45 ml/min, and dialysate flow rates of approximately 550 ml/min, the mean percentage of methylmercury cleared from blood passing through the dialyzer was 39%. Rates of elimination of methylmercury from the dog could be increased by a factor of 100 during the extracorporeal regional complexing hemodialysis procedure. Regional collimated counting of radioactivity along the length of the dog revealed a decline in all areas including the head region. The procedure was void of any noticeable side effects during treatment or as evidence by histological evaluation of liver and kidney after treatment.