Elevated blood pressure in the embryonic chick induced by a teratogenic dose of dextroamphetamine sulfate.

Previous work has demonstrated the cardiovascular teratogenicity of dextroamphetamine sulfate (0.25 mg/egg) in the 4-day (stage 24) chick embryo. Our current studies indicate that embryos treated with this teratogenic dose of d-amphetamine exhibit a mean ventricular blood pressure (MVBP) elevation for 1 hour at 4 hours after treatment. The mean MVBP value 4 hours after d-amphetamine treatment significantly exceeded the mean MVBP value for combined untreated and saline controls by 30%. Furthermore, d-amphetamine significantly decreased heart rate relative to controls by 6-9% at 2, 3, and 5 hours after administration. Elevation of embryonic blood pressure (measured by a water manometer system) during a critical period of aortic arch and ventricular septal morphogenesis is suggested as an etiological factor in the genesis of malformations of these structures.