Fig. 4.

Blocking α2-adrenoceptor treatment down-regulates immune response in trinitrobenzene sulphonic acid (TNBS)-induced colitis. Lamina propria mononuclear cells (LPMCs) were isolated from colonic tissues of mice with TNBS-induced colitis at the peak of the disease (day 4) and cultured with medium in the absence or presence of RX821002 (2 nM, 10 nM) or UK14304 (1 nM, 5 nM). After 15 min, the cells were stimulated further in the presence or absence of lipopolysaccharide (LPS) (50 ng/ml) for 8 h, then culture supernatants were collected and determined by enzyme-linked immunosorbent assay (ELISA), n = 5 in each group. (a) Concentration of tumour necrosis factor (TNF)-α in culture supernatants was measured by ELISA. *P < 0·01 compared with LPS + UK14304 (1 nM) or LPS + UK14304 (5nM); #P < 0·05 compared with LPS. (b) Concentration of interleukin (IL)-1β was measured by ELISA. *P < 0·01 compared with LPS, LPS + UK14304 (1nM) or LPS + UK14304 (5nM); #P < 0·05 compared with UK14304 (5 nM). (c) Concentration of IL-10 in culture supernatants was measured; no significant difference was found among those groups with or without stimulation of LPS.