Effect of acupuncture at complementary acupionts on mast cells and histamine/bradykinin released by mast cells in the regions of acupionts

Objective To observe the changes in numbers and degranulation status of local mast cells (MCs) of the complementary acupionts, as well as the concentrations of serum histamine and bradykinin after acupuncture at rat’s complementary acupionts of Yanglingquan (GB 34) and Yinlingquan (SP 10), for exploring the mechanisms of the synergistic effect of complementary acupionts. Methods Using random number table method, 40 Wistar rats were randomly divided into a blank control group (group K), an acupuncture at Yanglingquan (GB 34) group (group A), an acupuncture at Yinlingquan (SP 9) group (group B), an acupuncture at Yanglingquan (GB 34) and Yinlingquan (SP 9) group (group AB), and an acupuncture at points near Yanglingquan (GB 34) and Yinlingquan (SP 9) group (group CD), 8 rats in each group. Group A received acupuncture at Yanglingquan (GB 34); group B received acupuncture at Yinlingquan (SP 9); group AB received acupuncture at Yanglingquan (GB 34) and Yinlingquan (SP 9); group CD received acupuncture at the control points [points 3 mm away from Yanglingquan (GB 34) and Yinlingquan (SP 9) respectively]. Acupuncture was performed at bilateral points in each group. Rats in group K were fixed using the same method as rats in the other 4 groups without acupuncture stimulation. Needles of 0.35 mm in diameter and 40 mm in length were used for acupuncture. Needle handle was connected to the G6805-II mode electroacupuncture (EA) device after needling qi was obtained, with sparse-dense wave, frequency of 2 Hz/100 Hz and current of 1 mA to keep the needle handles slightly tremulous while the rats kept quiet. Rats were continuously stimulated by EA for 20 min each time. Experimental interventions were conducted on the 1st, 3rd, 5th and 7th days when the experiment started, for 4 times in total. Specimens from rats in each group were collected 2 h after the 7th day. The levels of histamine and bradykinin in serum were detected by enzyme-linked immunosorbent assay (ELISA). Local tissues of the points were used to prepare cryosections. The changes of MCs were observed after toluidine blue staining. Results Compared with group K, the numbers and degranulation rates of MCs in group A, group B, group AB and group CD were significantly increased (all P <0.05). The number and degranulation rate of MCs in group AB were significantly higher than those in group A, group B and group CD (all P <0.05). The order of histamine levels from high to low was: group AB > group B > group A > group CD > group K, and the differences were statistically significant (all P <0.05); the levels of bradykinin in group AB, group A and group B were significantly higher than those in group K and group CD (all P <0.05). There was no significant difference in the bradykinin level between group A and group B, nor between group CD and group K (all P >0.05). Conclusion The number and degranulation rate of MCs of the complementary acupionts are significantly increased after acupuncture at complementary acupionts of Yanglingquan (GB 34) and Yinlingquan (SP 9) of rats, and the serum levels of histamine and bradykinin are increased, which may be one of the mechanisms of the synergism produced by the combination of complementary acupionts.