PRENATAL EFFECTS OF BETAMETHASONE-L-CARNITINE COMBINATIONS ON FETAL-RAT LUNG

Lungs of fetal rats between the 18(th) and 20(th) gestational day (tot al gestation lasting 22 days) were examined. There was a significant i ncrease (p < 0.01) of the dipalmitoyl phosphatidylcholine content from day 19 to day 20 of gestation. In a second trial, pregnant rats were treated with different doses of betamethasone, L-carnitine, betamethas one-L-carnitine combinations, and saline (controls) for three days bef ore Cesarean section on the 19(th) gestational day. Maternal injection s of 0.10 ml/kg body weight betamethasone and 100 mg/kg body weight L- carnitine significantly (p < 0.05, p < 0.01 respectively) increased th e dipalmitoyl phosphatidylcholine content of fetal lungs. Combinations of either 0.05 or 0.10 mg/kg body weight betamethasone with 100 mg L- carnitine also significantly increased the dipalmitoyl phosphatidylcho line content of the fetal lungs above control values (p < 0.001) and v alues achieved with betamethasone alone (p < 0.05). Maternal treatment with a betamethasone-L-carnitine combination on day 19 of gestation r esulted in dipalmitoyl phosphatidylcholine levels comparable to those found on the 20(th) gestational day during normal lung maturation. Fet al rats delivered on the 20(th) gestational day survived, while fetuse s delivered on the 19(th) gestational day did not survive.