Experimental study on the protective effect of ulinastatin on lung tissue in rats with severe scalded

Abstract

Objective: To explore the potential protective effects of ulinastatin on ventilation-induced lung injuries of severe burned rats.

Methods: Ninety Wistar rats were randomly divided into three experimental groups: the control group (n = 30), the ventilation group (n = 30) and the ventilation-ulinastatin group (n = 30). After establishing the severe burn model, the rats of latter two groups were mechanically ventilated for 1 hour with or without the pre-treatment of ulinastatin. After severe scald, the protective effect of ulinastatin on lung injury caused by mechanical ventilation was estimated through the observation of the tissues samples, and evaluation of the pathological changes of lung tissue by HE staining, ultrastructure change by electron microscopy, lung coefficient, and the expression levels of lung tissue cytokines TNF-α, IFN-γ, IL-2 by immunohistochemical staining.

Results: Edema in lung tissues of the control group and the ventilation group was obvious, the hemorrhagic focus could be seen, and the cut surface was observed to be scattered and swelling; Edema in lung tissues of the ventilation-ulinastatin group was mild. HE staining revealed that the pathological changes of the ventilation-ulinastatin group were milder than the ventilation group. Under the electron microscope, the lung tissue organelles of the control group and the ventilation group were seriously damaged; the corresponding changes in the ventilation-ulinastatin group were lighter. The lung coefficient of the ventilationulinastatin group was significantly lower than that in the ventilation group. The immunohistochemical results showed that the intensity of TNF-α, IL-2 and IFN-γ in lung tissue of the ventilation-ulinastatin group was significantly lower than that in the ventilation group.

Conclusions: Ulinastatin has protective effects on lung injury caused by mechanical ventilation in severe scalded rats, whose mechanism may be related to the capacity of ulinastatin to reduce the expression of cytokines including TNF-α, IL-2 and IFN-γ.