Effect of Substance P on the Expression of Protease Activated Receptors in Macrophages and T Cells; Also Cytokines in the Peritonum
|School||Nanjing Medical University|
|Keywords||substance P macrophage T cells protease activated receptors IL-12 IL-6 eotaxin|
OBJECTIVE: To study the effect of substance P (SP) on the expression of protease activated receptors (PARs) in peritoneal macrophages and T cells from normal and allergic mice,and the level of IL-12、IL-6 and eotaxin in the peritoneal lavage fluid.METHOD: Normal and Allergic Balbc/c mice were separately divided into normal saline, 0.2, 2.0, 20 and 200μg/ml SP groups, with 6 mice in each group. Allergic mice were induced by ovalbumin (OVA): mice were sensitized at day 1,7,13 with 0.2ml solution [containing 50μg OVA and 1.5 mg Al (OH) 3)] and challenged with 1% OVA for 3 consecutive days (day 19, 20, 21) by intraperitoneal injection. 30 minutes prior to the last challenge, substance P at different concentration were injected intraperitoneally. Mice were sacrificed 3 hours after the final injection. Then collect the peritoneal lavage fluid, centrifuge in 1500 rpm for 8 min. The centrifuged cells were fixed with 2% paraformaldehyde.The expression of PARs on the surface of peritoneal macrophages and T cells were then analyzed by flowcytometry. IL-6、IL-12 and eotaxin in the mice supernatants of peritoneal lavage fluid were determined by the means of enzyme linked immunosorbent assay (ELISA).RESULTS: 1. PAR-1, PAR-2, PAR-3 and PAR-4 on the surface of peritoneal macrophages and T cells were all significantly decreased in allergic mice compared with normal mice (P<0.01). SP had no significant influence on expression of PARs in macrophages and T cells (P> 0.05). 2. IL-6, eotaxin levels in peritoneal lavage fluid were significantly higher in allergic mice than in non-allergic groups (P <0.01), while IL-12 the same (P> 0.05).The treatments of different concentrations of substance P had no significant differences (P> 0.05).CONCLUSION: The intraperitoneal injection of substance P had neither effect on the expression of PARs in macrophages and T cells nor IL-12, IL-6, eotaxin from mouse peritoneum, but OVA treatment did. Allergens play more important role in allergic diseases than substance P.