Maternal and developmental toxicity in mice by aminophenylnorharman,formed from norharman and aniline

Abstract

9-(4′-Aminophenyl)-9H-pyrido [3,4-b] indole (aminophenylnorharman, APNH) is a novel mutagenic heterocyclic amine, produced by the reaction of norharman with aniline in the presence of S9 mix. In the present study, the maternal and developmental toxicity of APNH were investigated in ICR mice administered oral doses of 0, 0.625, 1.25, 2.5 or 5 mg/kg/day on gestational days (GD) 6 through 15 or 0, 5, 10, or 20 mg/kg on GD 12. Maternal and foetal parameters were evaluated on day 18 of gestation. Foetuses of dams treated on GD 6–15 were examined for external and skeletal malformations and variations, and foetuses of dams treated on GD 12 were inspected for cleft palate. Maternal death occurred when APNH was administered at 5 mg/kg/day on GD 6 –15. No significant decrease in body weight gain during the administration period was observed at doses of 2.5 mg/kg/day or less when applied on GD 6– 15. Adverse changes in general condition of dams were observed in the groups treated at doses of 2.5 mg/kg/day and above on GD 6 –15, whereas no adverse effects on dams were noted even when APNH was applied at a fairly high dose on GD 12. Intracytoplasmic vacuolation in hepatocytes, necrosis of proximal tubular epithelial cells and desquamation of necrotic epithelial cells in the tubular lumen were observed in dams treated with APNH at 2.5 or 5 mg/kg/day on GD 6 –15. Increased pre-implantation loss was observed at 5 mg/kg/day and post-implantation loss was observed at 2.5 mg/kg/day and above when applied on GD 6–15, or at 20 mg/kg when applied on GD 12. Foetal body weight was decreased by APNH in a dose-dependent manner. The frequency of external malformations (cleft palate) was significantly increased in the group treated with APNH at 2.5 mg/kg/day on GD 6–15 compared to the controls. However, there were no foetuses with cleft palate even when APNH was given at 20 mg/kg on GD 12. No significant increases in skeletally malformed foetuses were found in any APNH-treated group. The frequency of lumbar ribs was increased dose dependently. This study demonstrated the develop-mental toxicity of a mutagenic compound, APNH, in mice at maternally toxic doses, and that cleft palate observed in term foetuses resulted from the adverse effect of APNH on the maternal environment during organogenesis. More detailed studies are warranted to assess the possible risks to pregnant women from exposure to APNH. Human & Experimental Toxicology (2002) 21, 147 – 151.

Keywords

aminophenylnorharman developmentaltoxicity humanexposure maternaltoxicity mice teratogenicity

References

Poindexter EH , Carpenter RD . The isolation of harman and norharman from tobacco and cigarette smoke . Phytochemistry 1962; 1: 215–21 .

Takase S , Murakami, H . Studies on the fluorescence of Sake: Part 1. Fluorescence spectrum of Sake and identification of harman . Agric Biol Chem 1966; 30: 869–76 .

Takeuchi T , Ogawa K , Iinuma H , et al. Monoamine oxidase inhibitors isolated from fermented broths . J Antibiot 1973; 26: 162 –67 .

Nagao M , Yahagi T , Kawachi T , et al. Comutagenic action of norharman and harman . Proc Jpn Acad 1977; 53: 95–98 .

Umezawa K , Shirai A , Matsushima T , Sugimura T . Comutagenic effect of norharman and harman with 2-acetylaminofluorene derivatives . Proc Natl Acad Sci USA 1978; 75: 928–30 .

Totsuka Y , Hada N , Matsumoto K , et al. Structural determination of a mutagenic aminophenylnorharman produced by the co-mutagen norharman with aniline . Carcinogenesis 1998; 19: 1995 –2000.

Totsuka Y , Kawamori T , Hisada S , et al. Testicular toxicity in F344 rats by aminophenylnorharman, formed from norharman and aniline . Toxicol Appl Pharmacol 2001; 175: 169 –75 .

Guide for the care and use of laboratory animals . NIH Publication 86-23. Bethesda, MD: National Institutes of Health , 1985.

Dawson AB . A note on the staining of the skeleton of cleared specimens with alizarin red S . Stain Technol 1926; 1: 123 –24 .

10.

Steel RGD , Torrie JH . Principles and procedures of statistics. New York: McGraw-Hill , 1960.

11.

Dunnet CW . New tables for multiple comparisons with a control . Biometrics 1964; 20: 482 –91 .

12.

Siegel, S . Nonparametric statistics for the behavioral sciences. New York: McGraw-Hill , 1956.

13.

Murakami G , Miyata Y , Shirai T , Arai M, Kawachi T , Ito N. Effects of the co-mutagen norharman in rats . Toxicol Lett 1979; 3: 157–61 .

14.

Nagao T . Frequency of congenital defects and dominant lethals in the offspring of male mice treated with methylnitrosourea . Mutat Res 1987; 177: 171 –78 .

15.

Wilson JG . In Wilson JG ed. Teratology <Eth> principles and technique. Chicago, IL: University of Chicago Press , 1965: 251-251.

16.

Kimmel CA , Wilson JG . Skeletal deviations in rats: malformations or variations? Teratology 1978; 8: 309– 316.

17.

Green EL . Quantitative genetics of skeletal variations in the mouse: II . Crosses between four inbred strains (C3H, DBA, C57BL, BALB/c). Genetics 1962; 47: 1085 –96 .