Effects of intrauterine IL-6 and IL-8 on the expression of surfactant apoprotein mRNAs in the fetal rat lung

Objective: The purpose of this study was to investigate the effect of inter leukin-6 (IL-6) and interleukin-8 (IL-8), whose concentrations are elevated with chorioamnionitis, on the expression of surfactant apoprotein mRNAs in fetal rat lung. Study design: We employed an animal model in which we were able to administer substances continuously into the cavity between the fet al membranes and endometrium using a miniosmotic pump. Lipopolysaccharide ( LPS), IL-6, or IL-8 was administered to timed pregnant rats for 3 days (day 16-19), and fetal lung expression of surfactant apoprotein mRNAs for SP (s urfactant apoprotein)-A, SP-B, and SP-C was evaluated by Northern blot hybr idization. Results: Continuous administration of LPS increased the expressi on of each surfactant apoprotein mRNA, but the expression of mRNAs was not dose-dependent. On the other hand, continuous IL-6 or IL-8 administration i ncreased the expression of each surfactant apoprotein mRNA in a dose-depend ent manner. Conclusion: Fetal lung maturation may be promoted by either IL- 6 or IL-8 produced in response to chorioamnionitis. (C) 2000 Elsevier Scien ce Ireland Ltd. All rights reserved.