ABSTRACT 489

Abstract

Background and aims: hyperoxia-induced oxidative stress plays a key role in pulmonary impairment of premature infant. Vasoactive intestinal peptide (VIP) is important to the regulation of the oxidative lung injury, cell proliferation and apoptosis as a pulmonary sensory neuropeptide. Aims: We investigated the protective effect of VIP on primary type II alveolar epithelial cells (AECIIs) after hyperoxia exposure. Methods: Primary AECIIs were isolated and purified from premature rats. Subsequently, the cells were exposed to air (21% oxygen), hyperoxia(95% oxygen), VIP+air, VIP+hyperoxia. The proliferation and apoptosis of AECIIs were analyzed with MTT cell proliferation assay, flow cytometry (FCM) and western blot detection of Proliferating cell nuclear antigen (PCNA). 2 ‘, 7’-dichloro-dihydrotestosterone fluorescein diacetate (DCFH-DA) molecular probe to measure the level of intracellular reactive oxygen species (ROS). Total antioxidant capacity (TAOC) was detected by ultraviolate spectro-photometer. Results: Compared with the simple hyperoxia treatment, the cell proliferation and apoptosis percentage was significantly increased and decreased after adding additional VIP. The increased level of PCNA could be found after adding VIP. Meanwhile, the levels of ROS were lower and TAOC was higher in hyperoxia+VIP than those in simple hyperoxia exposure. Conclusions: These data suggested that VIP can play a protective role by its anti-oxidant property in AECIIs after hyperoxia exposure, promoting AECIIs proliferation and inhibiting apoptosis, which attenuates hyperoxia-induced oxidative stress damage in AECIIs.