[Effects of encircled needling plus electroacupuncture on hyperplastic mammary glands and serum sex hormones in the rat].

OBJECTIVE

To observe the effect of encircled needling plus electroacupuncture (EA) of the second pair of nipples on hyperplastic mammary glands, serum estradiol (E2), progesterone (P), prolactin (PRL) and testosterone (T) contents, estrogen receptor (ER) expression of the mammary glands in mammary hyperplasia rats.

METHODS

Forty Wistar rats were equally randomized into normal control, model, acupuncture and medication groups. Mammary gland hyperplasia model was established by intramuscular injection of diethylstilbestrol (0.5 mg/kg, once daily for 25 days) and progesterone (4 mg/kg, once daily for 5 days). For rats of the acupuncture group, 4 filiform needles were inserted into the surrounding tissues of the second pair of breasts, respectively, followed by giving the animal with EA stimulation for 30 min. Another one acupuncture needle was inserted into "Danzhong" (CV 17) and retained for 30 min. For rats of the medication group, tamoxifen solution (1.8 mg/kg) was given by gavage. Both medication and EA intervention were given once daily for 30 days. The diameter and height of the second pair of nipples were measured before and on the 10th, 20th and 30th days of the treatment. Serum E2, P, PRL and T levels were assayed by radioimmunoassay, and the tissues of the second pair of nipples were stained with H. E. method. Estrogen receptor immunoactivity of the breast tissue was detected by immunohistochemistry.

RESULTS

The diameter and height of the second pair of nipples, serum E2, PRL and T contents, and breast ER protein expression level were significantly higher in the model group than in the normal control group (P<0.05), while serum P content was remarkably lower in the model group than in the normal control group (P<0.05). In comparison with the model group, the diameter and height of the second pair of nipples, serum E2, PRL and T contents, and breast ER protein expression level were considerably lower in both acupuncture and medication groups (P<0.05), and serum P contents were significantly higher in the latter two groups (P<0.05). In addition, H.E. staining showed that the numbers of the lobule, alveolus and ducts of mammary glands were significantly increased, and the expansion of the acinar lumina and ducts was found in the model group. These pathological changes were relatively milder in both acupuncture and medication groups.

CONCLUSION

Encircled needling plus EA stimulation of the surrounding tissues of the nipples can improve the hyperplasic nipples and pathological changes of the breast tissue in mammary gland hyperplasia rats, which is closely associated with its functions in lowering serum estradiol, prolactin, testosterone contents and estrogen receptor protein expression of the breast, and in increasing serum progesterone level.