The effects of exogenous interleukin-4 on hypoxia-induced lung injury

The aim of this study was to determine the effects of recombinant human interleukin-4 (rhIL-4) on hypoxia-induced lung injury in immature rats. The study was performed on 1-day-old Sprague Dawley rat pups. Group 1 (n = 7) served as nonhypoxic controls. Group 2 (untreated, n = 7) rats were subjected to hypoxia-reoxygenation (H/O) and were then returned to their mothers. Group 3 (rhIL-4 treated, n = 7) rats were subjected to H/O, were returned to their mothers, and were treated with rhIL-4 (75 microg/kg subcutaneously) for the next 3 days. All animals were killed on day 4 and lung specimens were obtained to determine the tissue level of malondialdehyde (MDA) and histological changes. In the untreated group, MDA levels were significantly increased compared to control and rhIL-4 groups. In the rhIL-4 treated group, MDA levels were not significantly different compared to control group. The rhIL-4 treated group had a significantly lower score of pathological lesions and alveolar hemorrhage grade values than the untreated group. The untreated animals had areas marked intraalveolar hemorrhage, capillary congestion, interstitial edema, and hypercellularity of lung that were not seen in the rhIL-4 treated rats. In conclusion, this study found beneficial effects of rhIL-4 in an experimental model on the hypoxia-induced lung injury.