Prenatal terbutaline exposure in the rat: selective effects on development of noradrenergic projections to cerebellum

Terbutaline, used in the treatment of premature labor and asthma, crosses the placenta and can stimulate beta 2-adrenergic receptors in the fetus. This study examines the effects of prenatal exposure to terbutaline (10 mg/kg SC on gestational days 17, 18 and 19) on the development of noradrenergic projections in brain regions of the fetal and neonatal rat, using synaptosomal uptake of [3H]norepinephrine as a marker for synaptogenesis. Although terbutaline exposure did not compromise body or brain region growth, uptake was adversely affected selectively in the cerebellum, a region which also displays close coupling of fetal beta 2-receptors to control of cell development near term. These results thus provide biochemical evidence that terbutaline may be a neurobehavioral teratogen.