The promotional effect of testosterone on induction of prostate-cancer in MNU-sensitized L-W rats.
Large metastasizing prostate adenocarcinomas (PAs) were induced in L-W rats by a single intravenous (i.v.) inoculation of methylnitrosourea (MNU) and then single subcutaneous implants of testosterone propionate (TP) at intervals of 2 months. This procedure induced PAs in approximately 90% of rats in an average of 11 months. PAs did not develop spontaneously in L-W rats under age 20 months. With this model system, it was demonstrated that within a 14-month observation period, significant numbers of PAs were elicited by TP implants in L-W rats after intervals of 1 week, 1 month and 2 months following the inoculation of MNU. A direct relationship was also demonstrated between amount of TP administered to L-W rats and the resulting incidence of PAs. TP is characterized as a prostate-directed promoter of PA, following a single inoculation of MNU which served as the tumor initiator.
Pollard
M
M
Lobund Laboratory, University of Notre Dame, IN 46556.
Luckert
P H
PH
Snyder
D L
DL
D000230:Adenocarcinoma / Q000139:chemically induced* / Q000473:pathology; D000818:Animals; D003043:Cocarcinogenesis; D004305:Dose-Response Relationship, Drug; D008297:Male; D008770:Methylnitrosourea / Q000633:toxicity*; D010173:Palpation; D011471:Prostatic Neoplasms / Q000139:chemically induced* / Q000473:pathology; D051381:Rats; D013739:Testosterone / Q000008:administration & dosage / Q000494:pharmacology*
D013739:Testosterone; D008770:Methylnitrosourea