Toxicological effects of paraquat on the histology of the stomach, small intestine and testis of male albino rat (Rattus norvegicus)

  • E B Debe
  • B N Okolonkwo
  • A A Ngokere


Background: Paraquat is a herbicide, commonly used by farmers in agriculture to prevent weed infestation. The non-target organic toxicity effect of this chemical motivated this study. Methods: Utilizing male albino rats of 0.2 kg average body weight, the LD100 (lethal dose that gave 100% death) for Paraquat was obtained as 1g/kg body weight Furthermore LD50 (median lethal dose of paraquat, ip) was obtained as 0.45 g/kg body weight using arithmetic method of karber. Six dose levels of paraquat 0, 0.09, 0.18, 0.35, 0.70, 1.00 g/kg body weight were administered intraperitoneally into the various groups of the male rats. Within 24hrs, histopathological examination in the stomach, in the small intestine and testis of the rats were performed. Results: Histopathological examination of the organs studied revealed that the stomach had mild mucosal ulceration, muscular coat atrophy, stromal oedema and tubular hyalinization which were dose-dependent. The small intestine showed mucosal ulceration, loss of villi, luminal and stromal oedema and glandular necrosis which were also dose dependent. Furthermore, the testis had classical central fibrosis, cellular polarization, tubular disorganization, necrosis and lack of mitotic figures (no cell division), oligospermia, azoospermia and hyperchromasia which were dose dependent. Conclusion: Paraquat, a notable herbicide used in agricultural weed control, had deleterious effects on such organs as stomach, small intestine and testes. Need therefore arises for caution in the handling of these chemicals as the danger of impairment of the gastrointestinal tract and indeed the reproductive system in males is a possibility.

Keywords: Paraquat, Acute toxic effects

Port Harcourt Medical Journal Vol. 2 (1) 2007: pp. 51-55

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eISSN: 0795-3038