Study on the regulatory mechanism of electroacupuncture based on thyroid pathway for mammary gland hyperplasia rats

Abstract

To study the regulating effect of thyroid pathway on electroacupuncture (EA) for mammary gland hyperplasia (MGH) so as to provide new research ideas for the mechanism of EA for MGH and to provide the evidence for clinical application. Sixty adult female SD rats were randomly divided into a blank group, a model group, an EA group, an EA with thyroidectomy group, an EA with sham operation group, 12 rats in each one. Except the blank group, the MGH model was established. Thyroid ablation was performed in the EA with thyroidectomy group, and sham operation was used in the EA with sham operation group, exposing thyroid without excision, 1 day after model establishment. EA was applied in the EA, the EA with thyroidectomy, and the EA with sham operation groups on the 4th day after model establishment, and not used in the other groups, but catching, routine disinfection and fixation were all the same as the above groups. The acupoints in the group A were bilateral "Tianzong" (SI 11), "Ganshu" (BL 18) and "Zusanli" (ST 36); and those in the group B were bilateral "Wuyi" (ST 15), "Hegu" (LI 4) and "Danzhong" (CV 17). The two groups of points were alternately used. EA, continuous wave, 2 Hz and 1 mA, was connected at "Tianzong" (SI 11) and "Ganshu" (BL 18), "Wuyi" (ST 15) and "Hegu" (LI 4) at the same side, 2 pairs EA a time, 20 min a time, once a day. All the intervention was given for 4 courses, 5 times as 1 course with 2 days between courses. After intervention, the height and diameter of the rat papilla were measured. Estrogen (E2) and progestational hormone (P) in the serum were detected by enzyme linked immunosorbent assay (ELISA), and the contents and protein expression of estrogen receptor α (ERα) and progesterone receptor (PR) in the mammary glands were detected by immunofluorescence and Western-blot. (1) The height and diameter of papilla in the model group increased compared with those in the blank group (both P<0.01). The height and diameter of papilla in the EA, EA with sham operation groups reduced compared with those in the model group (all P<0.01). Those in the EA with thyroidectomy group were lower than those in the model group, without statistical significance (both P>0.05). (2) Compared with the blank group, E2 increased and P decreased in the model group (both P<0.01). Compared with the model group, E2 decreased and P increased in the EA and EA with sham operation groups (all P<0.01). The contents of E2 and P had no statistical significance between the model and the EA with thyroidectomy groups (both P>0.05). (3) Compared with the blank group, the ERα content and protein expression increased and the PR content and protein expression decreased in the model group (all P<0.01). Compared with the model group, the ERα content and protein expression decreased and the PR content and protein expression increased in the EA and EA with sham operation groups (all P<0.01). The ERα and PR content and protein expression had no statistical significance between the model and the EA with thyroidectomy groups (all P>0.05). The effect of EA for MGH may be closely related to the regulation of thyroid.