title: Effect of phenobarbital on induction of liver and lung tumors by dimethylnitrosamine in newborn mice.
abstract: The effect of phenobarbital on simultaneous induction of liver and lung tumors was examined in inbred DDD mice. Group 1 of newborn mice received a single intraperitoneal (ip) injection of dimethylnitrosamine (DMN) and after weaning they were given 0.05% phenobarbital solution to drink. Group 2 received an injection of DMN like Group 1 but were then given normal water. Group 3 were injected ip with 0.9% NaCl solution and then given phenobarbital solution to drink as in Group 1, and Group 4 were injected with 0.9% NaCl solution like Group 3, and then given tap water to drink. The animals were examined 16 weeks after birth. In Group 1, 27 of 35 mice (77%) had liver tumor and 15 (43%) had lung tumor. In Group 2, 8 of 24 mice (33%) had liver tumor and 16 (67%) had lung tumor. Animals in Groups 3 and 4 did not develop tumors. The difference in the incidences of liver tumor, but not lung tumor, in Groups 1 and 2 was statistically significant (P less than 0.01); that is, a promoting effect of phenobarbital was observed in induction of liver tumor, but not lung tumor.
mesh_terms: D000236:Adenoma / Q000139:chemically induced*; D000818:Animals; D000831:Animals, Newborn; D004128:Dimethylnitrosamine; D004357:Drug Synergism; D008113:Liver Neoplasms / Q000139:chemically induced*; D008175:Lung Neoplasms / Q000139:chemically induced*; D051379:Mice; D009374:Neoplasms, Experimental / Q000139:chemically induced; D010634:Phenobarbital
chemical_list: D004128:Dimethylnitrosamine; D010634:Phenobarbital