Abstract:

[Abstract] Objective  To explore effects of acetylcholine chloride on nitric oxide (NO) produced by intestinal intraepithelial lymphocytes (IELs) in mice. Methods  IELs of Balb/c mice were isolated, cultured and incubated with acetylcholine chloride of various concentrations. Phytohemagglutinin (PHA) served as the control. NO in culture supernatants was detected with fluorospectrophotometry, IELs proliferation was determined by MTT, and intracellular Ca2+ ([Ca2+]i) was assayed by Fura-2/AM. Results  Compared with the control group of IELs (with concanavalin A (Con A) of 0.5 mg/L final concentration in the medium), absorbance (A) value decreased in each group of acetylcholine chloride 10-5, 10-6 and 10-7mol/L (P < 0.05). The level of NO in IELs supernatant was the lowest (without Con A in medium) on day 4, but the level of NO was then in? creased progressively and got the peak at day 7 (at the end of observation), which was higher than that of day 1, day 2, day 3 and day 4 (P < 0.05). In comparison with the control group of IELs, the level of NO in 10-5 mol/L acetylcholine chloride group and 10-2 g/L PHA group were significantly lower respectively (P < 0.05). There was no significant difference in the [Ca2+]i level in acetylcholine chloride group (P > 0.05), but it increased significantly in PHA group (P < 0.05). The level of NO in supernatants was positively correlated with common logarithm of [Ca2+]i of IELs only in acetylcholine chloride group (r=0.840，P = 0.036). Conclusion  Acetylcholine chloride can inhibit NO produced by IELs, which suggests that vagus nerve’s effect on controlling inflammation was possibly related to its ability to inhibit the production of NO.

Key words: intestinal intraepithelial lymphocytes, nitric oxide, acetylcholine chloride