Influence of desloratadine on rat enter-mast cells

Objective: To study the influence of desloratadine on rat enter-mast cells. Methods: Thirty SD male rats were divided into three groups randomly: control group, stress group and stress - desloratadin group. Rats in stress group and stress+desloratadine group were treated with chronic unpredicted mild stress. Open-field method was used to observe the change of the fecal pellet and rat behaviors (crossover and rearing). At the end of the experiment, with the method of rectal balloon distention, the perception thresholds and the number of abdominal withdrawal reflexes (AWR) of different balloon volume were observed as well as the effects of desloratadine on the numbers and the degranulation of rat mast cells. Results: The stress group rats had more conspicuous anxiety-like behaviors than the control group did (P<0. 05), but the behaviors seemed less in the stress+desloratadin group than in stress group (P<0. 05). The perception threshold of the stress and stress+desloratadin group was lower than that of control group (both P<0. 05). The number of AWR to the balloon content (1. 0 ml or 2. 0 ml) was higher in the stress group than that in the control group (P<0. 05), while was also higher than that in the stress+desloratadin group. The average fluorescence intensity of mast cells protein-1(mcp-1) in the stress group was less than that in control group and in the stress group (both P<0. 05). Conclusion: Chronic stress is associated with increased rectal motor activity, anxiety-like behaviors, and numbers of colonic mast cells. Desloratadine can decrease the number of mast cells in chronic stress rats, which may abirritate visceral hypersensitivity of chronic stress rats.