ABSTRACT
<p><b>OBJECTIVE</b>To observe the rule of the change of apoptosis and proliferation of pulmonary tissue cells in rats with inhalation injury, so as to explore the significance of apoptosis in the repairing process of pulmonary tissue injury.</p><p><b>METHODS</b>Smoke inhalation injury model was established in rats. The rats were randomly divided into normal control (NC) and smoke inhalation injury (SI) groups. TUNEL and immunohistochemistry methods were employed to determine the changes in cellular apoptotic and proliferating cell nuclear antigen (PCNA) indices of the pulmonary tissue at different postburn time points.</p><p><b>RESULTS</b>(1) The apoptotic index increased at 2 postburn hours (PBHs) and remained at high levels thereafter. (2) The PCNA index increased at 12 PBHs, reaching top level at 3 postburn days (PBDs), remaining kept at relativly high level later.</p><p><b>CONCLUSION</b>Apoptosis not only played roles in the early pulmonary injury after smoke inhalation injury, but also participated in the repair and modification of the proliferated tissue during later reconstruction.</p>