P-142: Adenosine Deaminase Activity during Menses, Follicular and Luteal Phases of Menstrual Cycle

Background: In recent years, numerous regulators of gonadal function have been studied. Adenosine deaminase(ADA) is widely distributed throughout human tissues and may contribute in the regulation of menstrual cycle. The purpose of this study was to determine the plasma activities of total adenosine deaminase (ADAT), and its isoenzymes, ADA1 and ADA2, and ADA1/ADA2 ratio during the menses, follicular and luteal phases of the menstrual cycle. Materials and Methods: Plasma activities of ADAT,ADA1, ADA2 and ADA1/ADA2 ratio were measured in 20 women aged 19-25 years and with regular menstrual cycle (26-30 days). For the menses, follicular and luteal phases, blood samples were obtained between 1-2, 7-8 and 21-22 days after beginning of menstruation, respectively. Results: Although, there were not significant differences in ADA and its isoenzymes activity during three phases of the menstrual cycle, but we observed regular pattern for alteration of ADA activity during menstrual cycle. The activity of ADAT, ADA1, ADA2 and ADA1/ADA2 ratio were the highest during the menses phase, the lowest during follicular phase and followed by increased during the luteal phase. Conclusion: Our results suggest that the change of ADA activity during menses, follicular and luteal phases might involve in the regulation of menstrual cycle. We speculate that reduction of ADA activity in follicular phase might lead to an increase in adenosine levels which may contribute in the ovulation process.