Objective To observe changes of microcirculation in the superficial regions of acupoints of the three Yin meridians of foot during the menstrual cycle in young college students

so as to provide experimental evidence for explaining the saying of traditional Chinese medicine that acupoints reflect the state of physiological and pathological activities of the internal organs. Methods Ninety healthy female volunteer college students were recruited in the present study. The subjects were asked to take a supine position on an examination couch to expose the Yuan-primary acupoints Taixi(KI3)

Taibai(SP3) and Taichong(LR3)

and Xi-cleft acupoints Shuiquan(KI5)

Diji(SP8) and Zhongdu(LR6) which are related to the uterus of the three Yin meridians of foot

the crossing acupoints of the three Yin meridians of foot Sanyinjiao(SP6)

non-specific acupoint of the Spleen meridian Xuehai(SP10)

non-related meridian acupoint Xuanzhong(GB39) and non-meridian-non-acupoint(being at the same level of GB39

between the Stomach and Gallbladder meridians on the lateral aspect of the lower leg). The laser speckle blood flow imaging technique was used to detect the state of microcirculation(average blood perfusion volume) during menstrual

follicular

ovulatory and luteal phases.Results The average blood perfusion volume(ABPV) of the right SP8 region was significantly lower in the menstrual phase than in the ovulation and luteal phases(P<0.05)

and in the follicular phase than in the ovulation phase(P<0.05). In the left LR6 region

the ABPV was obviously lower in the menstrual period than in the follicular

ovulation and luteal phases(P<0.05). In the SP8

SP6

KI3 and KI5 regions

the ABPV was significantly higher in each of the 4 phases on the left side than on the right side(P<0.05). In the right GB39

the ABPV in each of the 4 phases was apparently higher on the right side than on the left side(P<0.05). In the SP10 region

the ABPV was considerably higher on the left side than on the right side in the ovulation period(P<0.05). The ABPV of SP3 in the menstrual phase and that of the non-acupoint in the luteal phase were significantly higher on the right side than on the left side(P<0.05).Conclusion The blood perfusion of microcirculation in the superficial tissues of Xi-cleft acupoints SP8 and LR6 is obviously lower in the menstrual phase than in both of the ovulation and luteal phases in healthy young college students

which may specifically reflect the periodical activities of the uterus in the physiological state

and provide a basis of acupoint selection for menstrual healthy care.