[Regularity of body surface resistance at the acupoints of three yin meridians of the foot in reflecting physiological changes of the uterus].

Objective: To investigate the specific regularity of body surface resistance at different acupoints of the meridians associated with the uterus in reflecting menstrual cycle by observing the change in body surface resistance at source points, cleft points, confluent points, and non-specific points of three meridians of the foot in different menstrual cycles in normal female college students, to lay a foundation for the in-depth research on the mechanism of acupoints reflecting the function of , and to provide a reference for the clinical and scientific research on the biophysical characteristics of menstrual cycle-related acupoints in normal female.

Methods: A total of 90 normal female college students were recruited. The source points, cleftpoints, confluent points, and non-specific points of three yin meridians of the foot which were located in the adjacent spinal segments of the uterus were selected, and body surface resistance was monitored for 30 consecutive minutes at the same time-points of menstrual phase, follicular phase, ovulation phase, and luteal phase to observe the change in the resistance of each acupoint during the menstrual cycle.

Results: There was no significant change in the resistance value of unilateral acupoints during the menstrual cycle (>0.05). In the same period, there was no significant difference in resistance value between unilateral three source points, three cleftpoints, different acupoints of the spleen meridian, and different acupoints of lumbar 4 dermatomere (>0.05). As for the comparison of resistance of the same acupoint at the left and right sides, Taichong (LR3) at the left side had a higher resistance value than that at the right side in the menstrual phase (<0.05); Taibai (SP3) at the left side had a higher resistance value than that at the right side in the ovulation phase (<0.05); Zhongdu (LR6) at the left side had a higher resistance value than that at the right side in the follicular phase, the ovulation phase, and the luteal phase (<0.05); Taixi (KI3), Diji (SP8), and Sanyinjiao (SP6) at the left side had a higher resistance value than those at the right side in the menstrual phase, the follicular phase, the ovulation phase, and the luteal phase (<0.05); Shuiquan (KI5) at the left side had a lower resistance value than that at the right side in these four phases (<0.05).

Conclusion: The change trend of the resistance of the acupoints at the left and right sides associated with the three yin meridians of the foot can specifically reflect the change in qi and blood in the uterus during the menstrual cycle. The change trend of the source and cleft points of the liver meridian in the menstrual phase is different from that in the other phases, and the change trend of SP3, a source point of the spleen meridian, in the ovulation phase is different from that in the other phases, which suggests the specificity of meridian points in reflecting function. The mechanism by which meridian points reflect the function of zang-fu is associated with the meridian points and the spinal cord segments of , and meanwhile, it has a specific relationship with the meridians to which meridian points belong and the attributes of acupoints.