THE EFFECTS OF ORAL ADMINISTRATION OF MORPHINE SULPHATE ON FOETUSES OF SPRAGUE-DAWLEY RATS

Document Type: Regular Paper

Authors

Department of Biology, Faculty of Science Shahid-Beheshti University, Tehran, I. R. of Iran

Abstract

The deleterious effects of morphine sulphate addiction on the central nervous system are well
documented. Previous studies have shown that the passage of morphine from the placenta barrier can
influence the normal development of embryos, such as those of humans, by specific mechanisms. So, for
the first time, for the purpose of investigating the effects of morphine sulphate on pregnant animals,
three groups (control, sham and experimental) of Sprague-Dawley female rats were chosen and 0.1, 0.2
and 0.3 mg/ml of morphine sulphate were administered orally in drinking water to each female rat (n=5-
7) in four experimental groups in weeks 1, 2, 3 and 3 weeks of pregnancy. Caesarean sections were
performed at the end of the gestation period; foetuses (n=27-63) and their placentas were examined
externally; the number of foetuses and their resorption sites were also recorded. Results showed that 0.1,
0.2 and 0.3 mg/ml of morphine sulphate causes significant increase in the percentage of teratogenicity
(except in week 3) (p<0.05). Although 0.1mg/ml of morphine did not have any effect on the diameter
and weight of the placenta and the number of foetuses, 0.2 and 0.3 mg/ml of morphine caused a
significant decrease (p<0.05) in the weight and diameter of placentas, the number of the embryos, their
body weight and crown-rump length of fetuses. The foetal weight of all four groups decreased
significantly (p<0.05). These results also showed that teratogenic effects of oral administration of
morphine in rats mostly happens in week two (organogenesis) of embryonic development.

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