Relationship Between Parasympathetic Nerve Function and Ovarian Hormones During Different Phases of Ovarian Cycle In Healthy Young Women Latifa Afrin Dill Naher 1 , Noorzahan Begum 2 , Sultana Ferdousi 3 Abstract Background: Women having regular ovarian cycle often experience premenstrual syndrome which may be associated with alterations of autonomic nerve function due to fluctuation of ovarian hormones during different phases of ovarian cycle. Objective: To observe the parasympathetic nerve function status and their relationships with ovarian hormones during different phases of ovarian cycle in healthy young women. Methods: This cross sectional study was carried out in the department of Physiology at BSMMU, Dhaka in 2007 on 30 eumenorrhogic healthy females aged 20 to 30 years. Serum estrogen and progesterone were measured by MEIA method and parasympathetic nerve functions were assessed by valsalva, deep breathing test and orthostatic test during follicular and luteal phases of ovarian cycle. Data were analyzed by paired student t test, and Pearsons Correlation coefficient test where applicable. Results: Mean resting HR,SBP,DBP and all measures of parasympathetic nerve function were similar in all phases of ovarian cycle. With serum estrogen level, deep breathing showed significant (p<0.05) positive correlation in follicular and luteal phase and valsalva showed significant positive correlation during luteal phase. Conclusion: The results this study suggest that estrogen has got positive influence on parasympathetic nerve function which support cardioprotective role of estrogen in premenopausal females. Key words: Premenopausal women, estrogen, parasympathetic nerve function, follicular phase, luteal phase. J Bangladesh Soc Physiol. 2012 December; 7(2): 83-88 For Authors Affiliation, see end of text. http://www.banglajol.info/index.php/JBSP Introduction studies 2 . Internal environment of our body is largely controlled by the autonomic nervous system. Alteration of autonomic nerve function may be attributed to fluctuation of estrogen and progesterone in different phases of ovarian cycle 3 . Studies on experimental animal showed that estrogen has effect on the modulation of the cardiovascular autonomic functions as it has facilitatory influence on glumatergic neurotransmission, which is essential for Received: July 2012; Accepted : September 2012 omen in their reproductive age, often experience premenstrual syndrome like abdominal bloating, W weight gain, headache, fatigue, irritability, mood change, depression, tension etc. These symptoms usually subside within few days after the onset of menstruation 1 . This syndrome may be associated with the hormonal changes during luteal phase of ovarian cycle reported by 83 J Bangladesh Soc Physiol. 2012, December; 7(2): 83-88 Article