Effect of Human Epidermal Growth Factor on Lung Surfactant Production in Fetal Rabbit

Abstract

HIGUCHI, M., HIRANO, H. and MAKI, M. Effect of Human Epidermal Growth Factor on Lung Surfactant Production in Fetal Rabbit. Tohoku J. Exp. Med., 1989, 159 (1), 15-22 - The effect of human epidermal growth factor (hEGF) on the maturation of fetal rabbit lung was studied. On the 25th day of gestation, 0.1 ml of saline solution containing 0.1μg of hEGF was injected intramuscularly through uterine wall into fetuses in one horn of the uterus (hEGF treated group) and the same amount of saline solution injected into fetuses in the other horn of the uterus (saline-control group). Sham operated group was also studied; saline was injected to fetuses in both horns. On the 27th day of gestation, fetuses were delivered by cesarean section. There were no significant differences in fatal body weight and fetal lung wet weight among three groups. Total phosphatidylcholine (PC) and disaturated phosphatidylcholine (DSPC) concentrations/g dry lung weight were high in order of hEGF treated group, saline injected group and sham operated group. There were no significant differences in PC concentrations among three groups. However, DSPC concentrations in both saline-control and hEGF treated group were significantly higher than that in sham operated group (p< 0.01). The % composition of palmitic acid in PC molecule, which is the main component of saturated fatty acid of lung surfactant, was significantly higher in hEGF group than in sham operated group (p<0.05). Interestingly, there were no significant differences in DSPC level and the % composition of palmitic acid between saline-control and hEGF treated group. This phenomenon might be due to so called a “neighbor effect” that hEGF injected to fetuses in one side of the uterine horn influences the fetuses in the other side of the horn through placentas. These results suggest that hEGF accelerates the production of pulmo nary surfactant, but does not inhibit cell growth of fetal lung.