Absorption of methylmercury compounds from rat intestine.
Intestinal absorption of methylmercury complexed with non-protein sulfhydryl compounds (NPSHs) as occurs in bile was studied by means of direct injection of mercury compounds into ligated intestinal segments of rats. The extent of absorption of methylmercury-cysteinylglycine (MM-CysGly) was similar to that of methylmercury-cysteine (MM-Cys) and 1.5 times larger than that of methylmercury-glutathione (MM-GSH). This results suggested that MM-CysGly, which is recognized as a major component of methylmercury in rat bile, can be easily reabsorbed from the intestine. These results indicate that not only MM-GSH and MM-Cys but also MM-CysGly may play important roles in the intestinal reabsorption of methylmercury during its enterohepatic circulation. When the ligated intestine was pretreated with probenecid and acivicin, the intestinal absorption of MM-GSH was depressed much more than in the case of treatment with acivicin alone. This indicates the possibility that there are at least two systems for intestinal transport of MM-GSH, i.e. gamma-glutamyltranspeptidase (GGT)-dependent and -independent systems.
Urano
T
T
Department of Public Health, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.
Iwasaki
A
A
Himeno
S
S
Naganuma
A
A
Imura
N
N
D000818:Animals; D001646:Bile / Q000378:metabolism; D001665:Binding Sites; D001692:Biological Transport / Q000187:drug effects; D004357:Drug Synergism; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000378:metabolism*; D007555:Isoxazoles / Q000494:pharmacology; D008297:Male; D008767:Methylmercury Compounds / Q000008:administration & dosage / Q000378:metabolism*; D011339:Probenecid / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D007555:Isoxazoles; D008767:Methylmercury Compounds; C006303:acivicin; D011339:Probenecid