Studies on Gastro Intestinal Absorption of Mercury Compounds. I. Effect of Sulfhydryl Reagents on Rat Small Intestinal Absorption of Mercuric Chloride.

Abstract

The effect of SH reagents on the absorption of mercuric chloride through the rat small intestine was investigated by the in situ recirculation method. The concentrations of mercury in the perfusion solutions, intestine, blood, kidney and liver were determined at each time intervals. Without SH reagents, the mercury transfer into the blood increased slightly with the time proceeds and mercury was absorbed through the intestine. The addition of L-cysteine, glutathione, 3-mercapto-1, 2-propanediol, dimercaptosuccinic acid, D (-)-penicillamine, diethyldithiocarbamate (DDTC), pyridoxine-5-thiol and thiola did not promote the mercury absorption, nor decreased the mercury content in the perfusion solutions. On the other hand, 2, 3-dimercapto-1-propanol (BAL) and 2-mercaptoethanol (MET) distinctly increased the mercury concentration in the blood, and then promoted the absorption of mercury through the intestine. To investigate the mechanism of the mercury absorption, the effect of SH compounds on the partition coefficients of mercuric chloride between octanol and water was determined. BAL and MET greatly increased the partition coefficient, but most of the other SH reagents except DDTC rather decreased it. Therefore we conclude that the lipophilic chelate formation with SH reagents is the main mechanism for the promotion of mercury absorption through the intestine.