Summary
Granuloma formation is an inflammatory response of the host against invading pathogens or indigestible substances. We generated mesenteric oil granulomas by injecting pristane into the peritoneal cavity of mice, and oil granuloma formation in C57BL/6J and BALB/cByJ mice was compared. The formation and kinetics of oil granulomas were distinct between the two strains. In C57BL/6J mice, injected pristane induced oil granuloma formation at both the mesenteric centers (MG) and margins (SG). MG was resolving by 11 weeks, whereas SG persisted. In BALB/cByJ mice, MG developed slower but persisted longer than in C57BL/6J mice, whereas SG resolved sooner than in C57BL/6J mice. Injection of India ink revealed that phagocytes were mainly localized to the SG in C57BL/6J mice, but were diffusely located in both MG and SG of BALB/cByJ mice. SG cells expressed more monocyte chemotactic protein-1 mRNA than MG cells in C57BL/6J mice, but there was no difference in MCP-1 expression between the MG and SG in BALB/cByJ mice. These observations suggest that the recruitment of inflammatory leukocytes under the direction of chemokines differentiates the patterns of granuloma responses to pristane in C57BL/6J and BALB/cByJ mice.