Constrictive effects of paraquat on the ductus arteriosus in fetal rats.

Rats on day 21 of pregnancy received a subcutaneous injection of paraquat (2, 7 or 25 mg/kg). The inner diameter of the ductus arteriosus (DA) of their fetuses was measured using the whole-body freezing method 1, 3, 6 and 24 hours after injection. The 7 mg/kg dose group showed a significant constriction of the DA 3 hours after paraquat treatment. The 25 mg/kg dose group showed a significant constriction 3 and 6 hours after treatment. The constrictive effect was dose-dependent, that is, the magnitude of constriction observed 3 hours after paraquat injection was greater in the 25 mg/kg dose group than in the 7 mg/kg dose group. The 2 mg/kg dose group showed no significant change in the inner diameter of the DA at any point of measurement (1, 3, 6 and 24 hours after injection), compared to the saline treated controls. These results indicate that paraquat induces constriction of the fetal rat DA in a dose-dependent manner when administered in late stages of gestation, and that this effect of paraquat is not seen at a dose level of 2 mg/kg.

[1]  K. Shiota,et al.  Effect of acute maternal alcohol consumption on the fetal ductus arteriosus in the rat. , 1993, Biology of the neonate.

[2]  T. Takizawa,et al.  Constrictive effect of thyroxine on the ductus arteriosus in fetal rats. , 1993, Journal of Veterinary Medical Science.

[3]  T. Takizawa,et al.  Onset of the constrictive effect of indomethacin on the ductus arteriosus in fetal rats. , 1991, Acta anatomica.

[4]  K. Momma,et al.  Constriction of the Fetal Ductus Arteriosus by Glucocorticoid Hormones , 1981, Pediatric research.

[5]  K. Momma,et al.  Dilatation of the Ductus Arteriosus by Prostaglandins and Prostaglandin's Precursors , 1980, Pediatric Research.

[6]  M. Hollinger,et al.  The effects of ozone and paraquat on PGF2 alpha and PGE2 levels in plasma and combined pleural effusion and lung lavage of rats. , 1980, Environmental research.

[7]  G. Krishna,et al.  The effects of paraquat on prostaglandin synthesis of guinea pig lungs. , 1978, Toxicology.

[8]  S. Turner.  Prostaglandins and the lung. , 1978, The American review of respiratory disease.

[9]  L. Levine,et al.  Inhibition of arachidonic acid release from cells as the biochemical action of anti-inflammatory corticosteroids. , 1976, Proceedings of the National Academy of Sciences of the United States of America.

[10]  D. Robinson,et al.  Corticosteroids inhibit prostaglandin production by rheumatoid synovia , 1975, Nature.

[11]  S. Cagen,et al.  Fetal toxicity and distribution of paraquat and diquat in mice and rats. , 1975, Toxicology and applied pharmacology.

[12]  R. Elliott,et al.  The effects of prostaglandins, prostaglandin inhibitors, and oxygen on the closure of the ductus arteriosus, pulmonary arteries and umbilical vessels in vitro. , 1974, Prostaglandins.

[13]  P. Olley,et al.  The response of the ductus arteriosus to prostaglandins. , 1973, Canadian journal of physiology and pharmacology.

[14]  D. V. van Dorp,et al.  Comparative aspects of prostaglandin biosynthesis in animal tissues. , 1972, Biochimica et biophysica acta.