Objective:To study the effects of Simo Decoction on expression of NOS in cold - constraint stressed mice. Methods:Gastrointestinal dysfunction model was established by exerting the factors of cold - constraint stimulation. And then they were randomly treated with distilled water, Dieetel and SD. The expressions of NOS in brain tissue were meas- ured by immunohistoehemieal staining. The expressions of NOS in intestine were measured by RT - PCR. Result : The ex- pressions of NOS in brain tissue of model group was decreased significantly compar...