Lack of in vivo DNA binding of mercaptobenzothiazole to selected tissues of the rat.
In this study, the in vivo binding of 14C-labelled 2-mercaptobenzothiazole (MBT) to DNA was investigated. Male and female Fischer 344 rats were gavaged with 375 mg MBT/kg body weight and killed 8 hours later. DNA was extracted from the liver, adrenal glands, pituitary gland, pancreas, and bone marrow and the amount of radioactivity associated with the DNA was determined. Results from this study indicate that MBT does not significantly bind to DNA from any of the tissues examined. CBI values for liver for the 3 methods of purification were -1-3 which are on the low end of the covalent binding index. The CBI values for the other tissues were always less than 1. Other chemicals with similar CBI values include estrone and diethylstilbesterol. Strong hepatocarcinogens such as dimethylnitrosamine and aflatoxin have CBI values ranging from 6000 to greater than 20000.
Brewster
D W
DW
Monsanto Agricultural Company, Environmental Health Laboratory, St. Louis, MO 63110.
Mirly
K J
KJ
Wilson
A G
AG
Barnett
J W
JW
D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D052160:Benzothiazoles; D001853:Bone Marrow / Q000378:metabolism; D002250:Carbon Radioisotopes; D004247:DNA / Q000378:metabolism*; D005260:Female; D008099:Liver / Q000378:metabolism; D008297:Male; D010179:Pancreas / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D012737:Sex Factors; D013844:Thiazoles / Q000378:metabolism* / Q000493:pharmacokinetics; D014018:Tissue Distribution
D052160:Benzothiazoles; D002250:Carbon Radioisotopes; D013844:Thiazoles; C005563:captax; D004247:DNA