OBJECTIVETo study the roles of type II 11β-hydroxysteroid dehydrogenase (11β-HSD2) and it's signaling factors in the lung tissue in pathogenesis of persistent pulmonary hypertension (PPH) in neonatal rats.

METHODSSix Sprague-Dawley rats on the 19th day of pregnancy were randomly divided into PPH and control groups (n=3 each). The PPH group was intraperitoneally injected with indomethacin (0.5 mg/kg) twice daily and exposed in 12% oxygen for three days, in order to prepare a fetal rat model of PPH. The control group was intraperitoneally injected with an equal volume of normal saline and exposed to air. Neonatal rats were born by caesarean section from both groups on the 22nd day of pregnancy. In each group, 15 neonatal rats were randomly selected and sacrificed. 11β-HSD2 expression in the lung tissue of neonatal rats were observed by Confocal laser technology, and serum cortisol levels and prostacyclin, renin, angiotensin and aldosterone in the lung tissue of both groups were measured using ELISA.

RESULTS11β-HSD2 protein was widely expressed in the lung tissue of the control and PPH groups. The levels of 11β-HSD2 and prostacyclin in the lung tissue were lower in the PPH group than in the control group, while serum cortisol levels and renin, angiotensin and aldosterone in the lung tissue were higher in the PPH group than in the control group (P<0.05).

CONCLUSIONS11β-HSD2 and it's signaling factors play roles in pathogenesis of PPH in neonatal rats.