Superoxide dismutase in normal cycling human ovaries: immunohistochemical localization and characterization

Objective: To investigate the expression of manganese (Mn) and copper-zinc (Cu,Zn) superoxide dismutase (SOD) in normal cycling human ovaries throughout the menstrual cycle. Design: Descriptive, controlled study. Setting: Tohoku University School of Medicine. Patient(s): Twenty-four normal cycling human ovaries were obtained from patients who underwent oophorectomy and hysterectomy for squamous cell carcinoma of the uterine cervix. Intervention(s): Immunohistochemistry for Mn-SOD and Cu,Zn-SOD. Main Outcome Measure(s): Immunostaining. Result(s): In the follicular stage, Mn-SOD immunoreactivity was detected in granulosa and theca interna cells of steroid-producing follicles, that is, preantral, nondominant, dominant, and atretic follicles, whereas Cu,Zn-SOD was detected in theca interna cells of these follicles and in granulosa cells of dominant follicles. In the luteal stage, immunoreactivity for Mn-SOD and Cu,Zn-SOD was observed in both luteinized granulosa and theca cells of the functioning corpus luteum. In the early degenerating corpus luteum, both Mn-SOD and Cu,Zn-SOD were positive in steroid-producing luteinized theca cells. Mn-SOD immunoreactivity was also detected in nonsteroid-producing luteinized granulosa cells and macrophages. Conclusion(s): Our results suggest that the expression of Mn-SOD and Cu,Zn-SOD closely correlates with steroidogenesis in the human ovary. In addition, Mn-SOD may play an important role in the process of luteal regression.