Tumor promoting potential in male F344 rats and mutagenicity in Salmonella typhimurium of dipyrone.
For assessment of the carcinogenic potential and the mutagenicity of dipyrone, an antipyretic anodyne, -[(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl) methylamino]-methanesulfonic acid sodium salt monohydrate, three experiments were conducted using dipyrone A produced in Japan and/or dipyrone B obtained from the Federal Republic of Germany. (i) Carcinogenic potential of dipyrone A for rat liver: 8 week old male F344 rats were pretreated with 0.01% diethylnitrosamine (DEN) in drinking water for 2 weeks and, after 1 week of resting, administered 0.4% dipyrone in drinking water, 5 days a week, for 72 weeks. After an 8 week recovery period, all surviving rats were killed at 83 weeks. Hepatocellular carcinomas developed at a higher incidence in the DEN + dipyrone group (18 of 29 rats, 62%) than in the DEN alone group (9 of 29 rats, 31%), the difference being statistically significant (P less than 0.05). No carcinogenic activity of dipyrone was demonstrated in the groups given 0.4% dipyrone for 72 weeks or 0.4% dipyrone for 25 weeks, followed by 0.05% phenobarbital (PB) for 50 weeks. However, glutathione S-transferase P positive (GST-P+) preneoplastic hepatic foci in these groups were observed at a higher incidence than in the untreated control group (P less than 0.01). (ii) Effect of dipyrone A and dipyrone B on induction of DEN-initiated GST-P+ hepatic foci in a medium-term bioassay system: 0.4% dipyrone A in drinking water and 0.57% dipyrone A or dipyrone B in powdered diet after DEN initiation had similar enhancing effects on the development of GST-P+ foci (P less than 0.001). (iii) The Ames mutation test in Salmonella: both dipyrone A and dipyrone B proved weakly mutagenic for strain TA100 in the presence or absence of S9 fraction.
Izumi
K
K
Second Department of Pathology, School of Medicine, University of Tokushima, Japan.
Sano
N
N
Otsuka
H
H
Kinouchi
T
T
Ohnishi
Y
Y
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004052:Diethylnitrosamine; D004177:Dipyrone / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004326:Drinking / Q000187:drug effects; D007680:Kidney Neoplasms / Q000139:chemically induced; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced*; D008297:Male; D009153:Mutagens; D011230:Precancerous Conditions / Q000139:chemically induced; D051381:Rats; D011916:Rats, Inbred F344; D012486:Salmonella typhimurium / Q000187:drug effects
D009153:Mutagens; D004052:Diethylnitrosamine; D004177:Dipyrone