Sequential changes in the prostate of rats treated with chlormadinone acetate, testosterone and N-nitroso-N-methylurea.
An attempt was made to induce prostatic adenocarcinoma in rats. Temporary chemical castration of F344 rats was achieved by administration of diet containing 0.05% chlormadinone acetate (CMA) for three weeks. The prostate was then stimulated by three consecutive daily intramuscular injections of testosterone propionate (100 mg./kg.). On the day after the last testosterone injection, N-nitroso-N-methylurea (NMU) (50 mg./kg.) was injected intravenously. Animals were sacrificed 10 days and 4, 20, 40 and 60 weeks after NMU treatment. Well-differentiated adenocarcinomas were obtained in three of fifty-four animals (5.6%) by this treatment and a high incidence of simple hyperplasia (88%) and atypical hyperplasia (19%) was also observed at 60 weeks. More studies are necessary to develop a protocol resulting in more rapid induction of prostatic adenocarcinomas at higher incidence.
D000230:Adenocarcinoma / Q000139:chemically induced*; D000818:Animals; D002715:Chlormadinone Acetate; D008297:Male; D008770:Methylnitrosourea; D011467:Prostate / Q000187:drug effects / Q000473:pathology; D011471:Prostatic Neoplasms / Q000139:chemically induced*; D051381:Rats; D011916:Rats, Inbred F344; D013739:Testosterone; D013997:Time Factors
D002715:Chlormadinone Acetate; D013739:Testosterone; D008770:Methylnitrosourea