Expression of transforming growth factor-alpha, epidermal growth factor, and epidermal growth factor receptor in follicles of human ovarian tissue before and after cryopreservation

OBJECTIVE: To study the expression of transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), and EGF receptor in follicles of human ovarian tissue. DESIGN: A retrospective, controlled comparative study. SETTING: In vitro fertilization laboratory of a university hospital. PATIENT(S): Fifteen women with regular menstrual cycles who underwent laparoscopy and the biopsy of ovarian tissue. INTERVENTION(S): Paraffin sections were prepared from ovarian tissues, followed by immunohistochemical staining of TGF-alpha, EGF, and EGF receptor. MAIN OUTCOME MEASURE(S): Immunostaining for TGF-alpha, EGF, and EGF receptor in follicles of fresh and frozen ovarian tissues. RESULT(S): Immunoreactivities for TGF-alpha and EGF receptor were observed simultaneously in the oocytes of primordial, primary, preantral, and antral follicles. Strong staining for TGF-alpha and EGF receptor was present in thecal cells. The TGF-alpha and EGF receptor was also expressed in some granulosa cells of primary to antral follicles. The EGF only stained weakly in the oocytes of primordial and primary follicles and in thecal cells. There was no difference in staining patterns for TGF-alpha, EGF, and EGF receptor between fresh and frozen ovarian tissues. CONCLUSION(S): The TGF-alpha and EGF receptor was expressed in primordial to antral follicles, indicating a role of TGF-alpha in regulating follicular development through binding to the EGF receptor. Freeze-thawing did not substantially alter immunoreactivites for TGF-alpha, EGF, and EGF receptor in frozen ovarian tissue.