The researchers studied how insulin can protect rats from lung damage caused by inhaling smoke. They divided the rats into three groups: control, saline, and insulin. The insulin group received insulin injections after inhaling smoke, while the saline group received saltwater injections. The results showed that insulin helped reduce inflammation in the lungs and improved fluid buildup. Insulin also lowered blood sugar levels and decreased levels of inflammatory markers like TNF-α and IL-6. Additionally, insulin increased the levels of IL-10, a protective protein. Overall, the study found that insulin has protective effects on smoke-injured rats by reducing inflammation.