Carcinogenicity of 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) in the rat prostate and induction of invasive carcinomas by subsequent treatment with testosterone propionate.
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) at 400 ppm in the diet for 52 weeks was found to induce non-invasive microscopic carcinomas in the ventral prostate of the treated rats, in addition to colon and mammary carcinomas. The current experimental data demonstrate that only a 20-week period of PhIP treatment is sufficient for induction of ventral carcinomas and that long-term pharmacological dosing with testosterone propionate which applied through a Silastic tube embedded in the subcutis after PhIP treatment can induce invasive carcinomas in the anterior prostate and seminal vesicles. Thus, PhIP may provide the basis for a good two stage carcinogenesis model for investigation of prostate carcinogenesis.
Shirai
T
T
First Department of Pathology, Nagoya City University Medical School, Nagoya, Japan. tshirai@med.nagoya-cu.ac.jp
Cui
L
L
Takahashi
S
S
Futakuchi
M
M
Asamoto
M
M
Kato
K
K
Ito
N
N
D000818:Animals; D002273:Carcinogens / Q000008:administration & dosage / Q000633:toxicity*; D004357:Drug Synergism; D007093:Imidazoles / Q000008:administration & dosage / Q000633:toxicity*; D008297:Male; D009361:Neoplasm Invasiveness; D011471:Prostatic Neoplasms / Q000139:chemically induced* / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D013739:Testosterone / Q000008:administration & dosage*; D013997:Time Factors
D002273:Carcinogens; D007093:Imidazoles; D013739:Testosterone; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine