Valutazione immunoistochimica di frammentazione del DNA nucleare in follicoli ovarici umani pre-antrali

Aim. Aim of the current study is to determine the growing follicles in ovarian cortex in young women and to assess the percentage of DNA fragmentation in ovarian cells. Methods. Thin ovarian slices (1×1×5 mm) were obtained in 25 women (mean age 34.6, range 13-48) undergoing laparoscopy after informed consent. For each sample, 4 sections were cut for haematoxylin-eosin (EE) staining and Terminal Deoxynucleotidyl Transferase Mediated dUTP Biotin Nick End Labeling (TUNEL) in situ detection test. Results. One hundred forty-two primordial follicles, 50 primary follicles and 5 secondary follicles were recruited. The preantral follicles concentration in the ovarian cortex was inversely proportional to the patient's age (r2=-0.83; p<0.0001). Signals of nuclear DNA fragmentations (TUNEL positive) were observed in 28 (19.8%) out of 142 primordial follicles and in 11 (22%) out of 50 primary follicles. A statistical correlation was found between the follicular stage and apoptosis (r2=0.99; p<0.004). Conclusions. The present study suggests that apoptosis is a pivotal mechanism responsible for the selection of atretic follicles and follicles available for growing and ovulation.