Mouse granuloma pouch induced by Freund's complete adjuvant with croton oil

A mouse inflammation model of chronic proliferative type was newly produced in this study. Among a great many methods examined in mice, only an air-pouch method with Freund's complete adjuvant with 0.1% croton oil obviously induced the granuloma pouch with well-developed vascularization, which a little differed from that seen in rats. Both granuloma formation and fluid exudation in this adjuvant pouch increased until one or two weeks after treatment, respectively, followed by reducing gradually to become nearly normal at 12 weeks after. The pathohistological study exhibited liquefaction necrosis in the earlier stage, followed by coagulation necrosis accompanied with inflammatory cells infiltration. The nascently sprouted capillaries were well-developed and then the fibrous tissue formation proceeded along with the vascularization. The granuloma finally changed to scars and callous tissues. Intrapouch injection of hydrocortisone and indomethacin decreased the pouch fluid and the pouch wall weight. In conclusion, the adjuvant pouch in mice may be a feasible experimental model for the pharmacological study on the vascularization in the acute and chronic inflammatory processes.