Kisspeptin: a new marker for human pre-ovulation.

Kisspeptin is a polypeptide that plays an important role in reproductive endocrine regulation. The aim of present study was to investigate the dynamic trend of kisspeptin levels during the menstrual cycle and to elucidate the relationship between kisspeptin ovulation. First, 15 female volunteers with regular menstrual cycles were recruited to detect the change in serum and urine kisspeptin levels over one menstrual cycle within each individual. Subsequently, 114 serum samples and 79 urine samples from 114 individuals were randomly collected at the outpatient department to better ascertain the results. Kisspeptin levels showed a distinctive stage-specific pattern during the normal menstrual cycle in both serum and urine. It was low during the first 5 days, while the first surge appeared on the 11th day (the diameter of the dominant follicle was approximately 1.2 cm). Later, a second smaller surge appeared around the 14th day and the same changes were identified in serum and urine. Furthermore, serum kisspeptin levels were positively related to 17-β estradiol (E) level increase. Thus, kisspeptin surge in serum and urine may be used as a marker for dominant follicle development and pre-ovulation. Moreover, kisspeptin may also play a vital role in female reproduction through regulating hormonal state.