Objective: To observe the influence of acupuncture stimulus and thermal stimulus on the expression of mast cells(MCs) and 5-hydroxytryptamine(5-HT) in local acupoint area of Guanyuan (关元 CV 4) and serum 5-HT in rats. Methods: Thirty-nine male C57BL/6 rats were randomly divided into blank control group, acupuncture stimulus group and thermal stimulus group, with 13 rats in each group. The rats were stimulated by manual acupuncture at CV 4 for 5 min in acupuncture stimulus group, while those in thermal stimulus group were stimulated by adopting...