Expression of Potassium Channels in Uterine Smooth Muscle Cells from Patients with Adenomyosis

Background: Adenomyosis (AM) has impaired contraction. This study aimed to explore the expression of potassium channels related to contraction in myometrial smooth muscle cells (MSMCs) of AM. Methods: Uterine tissue samples from 22 patients (cases) with histologically confirmed AM and 12 (controls) with cervical intraepithelial neoplasia were collected for both immunohistochemistry and real-time polymerase chain reaction to detect the expression of large conductance calcium- and voltage-sensitive K+ channel (BKCa)-alpha/beta subunits, voltage-gated potassium channel (Kv) 4.2, and Kv4.3. Student's t-test was used to compare the expression. Results: The BKCa-alpha/beta subunits, Kv4.2, and Kv4.3 were located in smooth muscle cells, glandular epithelium, and stromal cells. However, BKCa-alpha subunit expression in endometrial glands of the controls was weak, and Kv4.3 was almost undetectable in the controls. The expression of BKCa-alpha messenger RNA (mRNA) (0.62 +/- 0.19-fold decrease, P < 0.05) and Kv4.3 mRNA (0.67 +/- 0.20-fold decrease, P < 0.05) decreased significantly in the MSMCs of the control group compared with the AM group. However, there were no significant differences in BKCa-beta subunit mRNA or Kv4.2 mRNA. Conclusions: The BKCa-alpha mRNA and the Kv4.3 mRNA are expressed significantly higher in AM than those in the control group, that might cause the abnormal uterus smooth muscle contractility, change the microcirculation of uterus to accumulate the inflammatory factors, impair the endometrium further, and aggravate the pain.