Polycystic ovary syndrome: brain-derived neurotrophic factor (BDNF) plasma and follicular fluid levels.

Polycystic ovary syndrome is one of the most common endocrine disorders in women of reproductive age. Features of PCOS are hyperandrogenism, chronic anovulation and polycystic ovaries on ultrasonography. Follicle development is a complex and carefully orchestrated phenomenon, involving gonadotropins and a rapidly expanding list of other intraovarian regulators, such as brain-derived neurotrophic factor (BDNF). The aim of this study is to evaluate BDNF in plasma and in follicular fluid in women affected by PCOS and in normal menstruating women. In PCOS patients the BDNF levels in plasma and in follicular fluid are higher than values obtained in healthy controls. Therefore we can hypothsize that high levels of luteinizing hormone, probably increase the secretion of BDNF in PCOS patients.

Evaluation of brain-derived neurotrophic factor in menstrual blood and its identification in human endometrium.

The presence of high-affinity brain-derived neurotrophic factor receptor Trk B in mouse and in human fetal oocytes, together with the presence of neurotrophins in human follicular fluid suggests a paracrine role for brain-derived neurotrophic factor (BDNF) in female biology. This study aims to evaluate if BDNF is present and quantitatively determined in human menstrual blood and endometrium. Twenty-one women were studied and subdivided in two groups: A, 11 fertile women (27 ± 2 days cycle length) and B, 10 anovulatory women and/or women with inadequate luteal phase (36 ± 2 days cycle length). In fertile women menstrual BDNF levels was higher than plasma (679.3 ± 92.2 vs 301.9 ± 46.7 pg/ml p <0.001). Similarly, in Group B, BDNF in menstrual blood was higher than plasma (386.1 ± 85.2 vs 166.8 ± 24.1 pg/ml p < 0.001). Moreover, both menstrual and plasma BDNF concentrations in Group A were significantly higher respect to Group B (679.3 ± 92.2 vs 386.1 ± 85.2 pg/ml p < 0.001; 301.9 ± 46.7 vs 166.8 ± 24.1 pg/ml p < 0.001). Immunohistochemistry evidence of BDNF in endometrium, during follicular and luteal phase, was also shown. The detection of BDNF in the human menstrual blood and endometrium further supports the role of this neurotrophin in female reproductive function.