Phenobarbital promotes multistage pulmonary carcinogenesis in MNU-inoculated L-W rats.
Lobund-Wistar (L-W) rats develop adenocarcinomas spontaneously in the accessory sex glands (prostate-seminal vesicles) (P-SV) in the livers and in the lungs-all after long periods of latency. This report addresses (a) the multistage pattern of induced lung carcinomas in L-W rats and (b) the role(s) of two putative promotional agents (testosterone propionate (TP) and phenobarbital (PB) in the development of carcinomas in the lungs of L-W rats. Lung cancer is a rare slow-growing spontaneous neoplasm in L-W rats. Their incidence increased from 4.4% in avg 25.6 months (spontaneously) to 23.8% in avg 19 months following a single IV inoculation of methylnitrosourea (MNU), and further increased to 57% in avg 15 months by adding phenobarbital to the diet of MNU-inoculated rats. Three stages of lung tumorigenesis were manifested in L-W rats following treatments with MNU, or MNU + PB: hyperplasia, adenoma, and carcinoma.
Pollard
M
M
Lobund Laboratory, University of Notre Dame, IN 46556, USA.
Luckert
P H
PH
D000230:Adenocarcinoma / Q000139:chemically induced*; D000236:Adenoma / Q000139:chemically induced*; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D002273:Carcinogens; D006801:Humans; D006965:Hyperplasia; D007223:Infant; D008175:Lung Neoplasms / Q000139:chemically induced*; D008770:Methylnitrosourea; D009367:Neoplasm Staging; D010016:Osteoma / Q000139:chemically induced; D010634:Phenobarbital / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013047:Specific Pathogen-Free Organisms; D013739:Testosterone / Q000494:pharmacology
D000927:Anticonvulsants; D018931:Antineoplastic Agents, Hormonal; D002273:Carcinogens; D013739:Testosterone; D008770:Methylnitrosourea; D010634:Phenobarbital