Lack of promoting activity of 7-methoxy-2-nitro-naphtho-[2,1-b]furan (R7000) in a medium-term rat liver bioassay.
Among the nitro-naphthofurans, 7-methoxy-2-nitro-naphtho[2,1-b]furan (R7000) has proved to be a very potent mutagen that causes sarcomas at the subcutaneous injection site and carcinomas in the forestomach after p.o. administration. In the present study, possible promoting activity for diethylnitrosamine (200 mg/kg, i.p.)-initiated liver carcinogenesis was assessed in rats. R7000 dissolved in 5% ethanol solution at doses of 10 or 50 mg/l given as the drinking water for 6 weeks did not enhance development of pre-neoplastic glutathione S-transferase placental form positive foci. Thus, it was concluded that R7000 may not be carcinogenic for the rat liver under the present experimental conditions.
Cui
L
L
First Department of Pathology, Nagoya City University Medical School, Japan.
Hasegawa
R
R
Zajdela
F
F
Puapairoj
P
P
Shirai
T
T
Ito
N
N
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002273:Carcinogens / Q000633:toxicity*; D005982:Glutathione Transferase / Q000032:analysis; D007527:Isoenzymes / Q000032:analysis; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects / Q000201:enzymology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000201:enzymology; D008297:Male; D009153:Mutagens / Q000633:toxicity*; D009581:Nitrofurans / Q000633:toxicity*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors
D002273:Carcinogens; D007527:Isoenzymes; D009153:Mutagens; D009581:Nitrofurans; C030911:2-nitro-7-methoxynaphtho(2-1b)furan; D005982:Glutathione Transferase