Effects of epidermal growth factor (EGF) on the development of EGF-receptor (EGF-R) binding in fetal rabbit lung organ culture.
Epidermal growth factor (EGF) causes gender- and development-specific changes in fetal lung surfactant synthesis. We hypothesized that the effects of EGF on development of surfactant synthesis are related to effects on EGF receptor (EGF-R) expression. We prepared sex-specific fetal rabbit lung organ cultures on gestational days 21 and 24 (term = 31 days) in Waymouth's medium + 10% charcoal-stripped fetal calf serum as control or with added EGF (10 ng/mL). After 3, 5, and 7 days of culture, we measured specific EGF-R binding in fetal lung plasma membrane preparations. Analysis of variance (ANOVA) revealed significant effects of fetal gender (P = 0.0003), time in culture (P = 0.01), and EGF treatment (P = 0. 0003) on EGF specific binding. In control cultures from days 21 and 24 (both male and female), EGF specific binding tended to decrease with time in culture. Specific binding in EGF-treated female 21-day cultures was significantly higher than in controls, both after 5 days (184% of control, P = 0.007) and after 7 days (151% of control, P = 0.01; Bonferroni multiple comparisons) of treatment, whereas males exhibited no response to EGF treatment. As opposed to these effects in 21-day cultures, EGF had little effect on 24-day cultures. We conclude that EGF affects the expression of the EGF-R on EGF specific binding in the fetal lung. The development of surfactant synthesis in the fetal lung may be controlled by upregulation of the EGF-R.
Villanueva
D
D
Hospital Infantil de México "Federico Gómez," Mexico City, Mexico.
McCants
D
D
Nielsen
H C
HC
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D005325:Fetal Organ Maturity; D005333:Fetus; D005865:Gestational Age; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009924:Organ Culture Techniques; D011247:Pregnancy; D011663:Pulmonary Surfactants / Q000096:biosynthesis; D011817:Rabbits; D015854:Up-Regulation
D011663:Pulmonary Surfactants; D004815:Epidermal Growth Factor; D066246:ErbB Receptors