Discrimination of transport systems for methylmercury uptake in rat erythrocytes using methylmercury-mercaptalbumin by inhibitors and other factors.
This is a continuation of studying the transport system for the uptake of methylmercury (MeHg). The aim of the current study was to study transport systems in rat erythrocyte for the uptake of MeHg while using MeHg-mercaptalbumin (MeHgMASH) complex. The uptake of methylmercury was studied in isolated erythrocytes from rats at 5 degrees C. Different reagents were used to study different transport systems in rat erythrocytes: adenosine 5'-triphosphate (ATP), ouabain and sodium fluoride for the active transport systems; probenecid for the organic anion transport system; 4',4-diisothiocyano-2',2-stilbenedisulphonic acid (DIDS), maleimide and N-ethylmaleimide for Cl- transport system; verapamil for Ca2+ ion transport system; colchicine and vinblastine for the microtubule system; verapamil for Ca2+ ion transport system; colchicine and vinblastine for the microtubule system; valinomycin for the effect of membrane potential; hexanol for the protein-mediated transport system and nonelectrolyte diffusion. The results showed that the uptake of MeHg might be involved in several transport systems: the active transport systems, an organic anion transport system, Cl- ion transport system, and Ca2+ ion transport system. The transport systems were slightly sensitive to the membrane potential. These transport systems seem to share similarities with the transport systems for the uptake of MeHg when using MeHg-cysteine and MeHg-glutathione complexes.
Wu
G
G
Biochemistry Section, National Institute for Minamata Disease, Kumamoto, Japan.
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D004912:Erythrocytes / Q000378:metabolism*; D008297:Male; D008628:Mercury / Q000378:metabolism*; D011339:Probenecid / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014634:Valinomycin / Q000494:pharmacology
D014634:Valinomycin; D000255:Adenosine Triphosphate; D008628:Mercury; D011339:Probenecid; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid