Abstract
In a previous experiment, fetopathic effects of caffeine were significantly reduced by pretreatment with propranolol at dosage levels of 2.5 to 10 mg/kg. The present experiments were undertaken to investigate the relation between time intervals of propranolol pretreatment and its effect on reducing fetopathy. Furthermore, the effect of timolol, another β-adrenergic blocking agent, on reducing fetopathy was compared with that of propranolol. Propranolol (5 mg/kg) administered 15, 30 or 60 minutes before caffeine treatment significantly reduced the caffeine-induced fetopathy. The optimal effect was found when propranolol was given 30 minutes before caffine. The reduction in fetopathy by timolol pretreatment was comparable to that of propranolol. The results lend support to the hypothesis that the fetopathic effect of caffeine is linked with released catecholamines in maternal or fetal tissues of mice.
