Effects of scopolamine hydrobromide on the development of the chick and rabbit embryo.

When 100 or 200 microgram of scopolamine hydrobromide were injected into hen eggs after they had been incubated for 96 h the major malformations of the embryo found were gastroschisis, exencephaly, reduction deformities of the limbs, microphthalmia and buphthalmia when the eggs were opened on the 12th day of incubation. Eight foetuses of one of eight New Zealand white rabbit does given scopolamine hydrobromide at the rate of 473 microgram/kg in their drinking water from the 10th to the 14th day of gestation showed malformations consisting of microphthalmia, buphthalmia, exencephaly and hydrocephaly. A second doe which similarly received 520 microgram/kg of the hydrobromide had four malformed foetuses showing microphthalmia and had two foetuses which were resorbed. However, there were no malformations in foetuses of eight does given bolus doses of scopolamine hydrobromide ranging from 37 to 184 microgram/kg by intramuscular injection every 12 h from the 10th to the 14th day of gestation. Results indicate interference by the drug with the function of the cholinergic nerves on the development of the chick and rabbit embryo.