Carcinogenic potential of some pesticides in a medium-term multi-organ bioassay in rats.
The carcinogenic potential of 5 pesticides was analyzed using a medium-term multi-organ bioassay for carcinogenicity. Male F344 rats were initially treated with 3 known carcinogens (diethylnitrosamine, N-methyl-N-nitrosourea and N-bis(2-hydroxypropyl)nitrosamine) during a period of 4 weeks to induce neoplastic changes in a variety of organs, and then given one of 5 pesticides in the diet for a further 16 weeks. Neoplastic and pre-neoplastic lesions were found in the thyroid, kidney and urinary bladder with propineb, in the forestomach, kidney and thyroid with captan and folpet. The number of glutathione S-transferase placental-form-positive liver-cell foci was significantly increased in the captan- and phosmet-treated groups. Based on these findings, captan and propineb can be considered as carcinogens and carcinogenicity is suspected for folpet and phosmet. These results are in concordance with reported long-term carcinogenicity for captan, folpet and propineb. Daminozide was considered not to be carcinogenic. Thus, the present assay of 20 weeks' duration is useful for the prediction of potential carcinogens.
First Department of Pathology, Nagoya City University Medical School, Japan.
R
R
Hasegawa
R
R
Cabral
T
T
Hoshiya
K
K
Hakoi
T
T
Ogiso
P
P
Boonyaphiphat
T
T
Shirai
N
N
Ito
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002215:Captan / Q000633:toxicity; D015197:Carcinogenicity Tests; D002273:Carcinogens / Q000633:toxicity*; D003043:Cocarcinogenesis; D004052:Diethylnitrosamine; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced; D008297:Male; D008770:Methylnitrosourea; D008954:Models, Biological; D009602:Nitrosamines; D009929:Organ Size / Q000187:drug effects; D010575:Pesticides / Q000633:toxicity*; D011230:Precancerous Conditions / Q000139:chemically induced; D051381:Rats; D011916:Rats, Inbred F344; D015038:Zineb / Q000031:analogs & derivatives / Q000633:toxicity
D002273:Carcinogens; D009602:Nitrosamines; D010575:Pesticides; C012509:propineb; D004052:Diethylnitrosamine; C012457:diisopropanolnitrosamine; D008770:Methylnitrosourea; D002215:Captan; D015038:Zineb