title: The sex difference in type II cell surfactant synthesis originates in the fibroblast in vitro.
abstract: Lung from 19 days' gestation male and female rat fetuses was grown in mixed monolayer culture. Cultures from female lungs synthesized twice as much 3H-saturated phosphatidylcholine (3H-SPC) from 3H-choline as cultures from male lungs. Preincubation with cortisol caused a doubling in 3H-SPC synthesis by cultures from both sexes. Study of sex-specific fibroblast cultures revealed significantly higher 11-oxidoreductase activity and basal and cortisone- or cortisol-stimulated fibroblast-pneumonocyte factor activity in female cultures. In contrast to the findings in the fibroblast cultures, sex-specific type II cell cultures showed no difference in basal 3H-SPC synthesis or in response to cortisol-stimulated fibroblast-conditioned medium. Furthermore, the type II alveolar cells had no 11-oxidoreductase activity. These data indicate that there are sex differences in both cortisol metabolism and fibroblast-pneumonocyte factor production by the fetal lung fibroblast. These differences would lead to a sex difference in the synthesis of pulmonary surfactant.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D008168:Lung / Q000196:embryology / Q000378:metabolism*; D008297:Male; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D011650:Pulmonary Alveoli / Q000166:cytology / Q000378:metabolism*; D011663:Pulmonary Surfactants / Q000096:biosynthesis*; D051381:Rats; D012737:Sex Factors
chemical_list: D010713:Phosphatidylcholines; D011663:Pulmonary Surfactants