If my first experiment was just using IR model, I think I would use about 6 mice.(1) Under normal circumstances, explore the distribution of mast cells and macrophages in the lungs of old and young mice;(2) In the IR model, we investigated the distribution of rtem neutrophils in the lungs of old and young mice;(3) In the IR model, we explored the distribution of mast cells and macrophages in the lungs of old and young mice;(4) In the IR model, we explored the interactive dialogue between rtem neutrophils and mast cells;(5) In the IR model, we explored the interactive dialogue between rtem neutrophils and macrophages;In conclusion: (1) under normal conditions and IR model: explore the distribution differences of mast cells and macrophages in the lungs of old and young mice, as well as the differences of vascular morphology and density;(2) In the IR model, we explored the differences in the distribution of rtem neutrophils in the lungs of old and young mice, as well as the differences in vascular morphology and density;(3) In the IR model, we explored the interaction between rtem neutrophils and mast cells or macrophages;Mouse usage:Comparison under normal conditions: (3:3)Comparison under IR model: (3:3)