Para-methoxyphenol strongly stimulates cell proliferation in the rat forestomach but is not a promoter of rat forestomach carcinogenesis.
The modifying effects of para-methoxyphenol (PMP) second stage treatment on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-initiated rat forestomach carcinogenesis were investigated. Groups of 15 6 week old male F344 rats were given a single intragastric administration of 150 mg/kg body wt MNNG and starting 1 week later were administered powdered diet containing 2.0, 1.0, 0.5, 0.25 or 0% PMP until they were killed at week 52. PMP caused epithelial damage and hyperplasia in a dose-dependent manner in the forestomach epithelium, but nevertheless was not associated with any increase in the incidence of either papillomas or squamous cell carcinomas. The results thus clearly indicated that stimulation of cell proliferation does not necessarily correlate with promotion in the second stage of two-stage forestomach carcinogenesis.
First Department of Pathology, Nagoya City University Medical School, Japan.
S
S
Wada
M
M
Hirose
S
S
Takahashi
S
S
Okazaki
N
N
Ito
D000818:Animals; D000840:Anisoles / Q000633:toxicity*; D015197:Carcinogenicity Tests; D002277:Carcinoma / Q000139:chemically induced / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D006965:Hyperplasia; D008297:Male; D008769:Methylnitronitrosoguanidine / Q000633:toxicity; D009130:Muscle, Smooth / Q000187:drug effects / Q000473:pathology; D009929:Organ Size / Q000187:drug effects; D010212:Papilloma / Q000139:chemically induced / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D013270:Stomach / Q000187:drug effects / Q000473:pathology*; D013274:Stomach Neoplasms / Q000139:chemically induced* / Q000473:pathology
D000840:Anisoles; D008769:Methylnitronitrosoguanidine; C009760:mequinol