The influence of long-term administration of terbutaline on the disaturated phosphatidyl-choline concentration of fetal lung tissue and amniotic fluid in pregnant rabbits.

Abstract

AbstractTerbutaline (40 μg/kg) was given intramuscularly to pregnant rabbits three times daily from the 23rd day of gestation until the 26th to 30th days, when the fetuses were delivered by cesarean section. The wet lung weight/body weight ratio of fetuses significantly decreased in the terbutaline‐treated group on the 27th and 28th days as compared with the control. The concentration of disaturated phosphatidyl‐choline (DSPC) of fetal lung tissue significantly increased only on the 29th and 30th days of gestation, which corresponded to the 7th and 8th days after the administration of terbutaline. However, a significant increase of the DSPC concentration in amniotic fluid had already occurred from the 26th day. These findings indicate that terbutaline accelerates the lung surfactant release, but does not primarily stimulate the synthesis of lung surfactant. The acceleration can be achieved only by long‐term administration of terbutaline. As this drug is able to dehydrate the fetal lung tissue by reducing the lung fluid, it might contribute to the stabilization of pulmonary respiration after birth.