Effects of isolating methods (mechanical or enzymatical) on structure of pre-antral follicles in mouse

Abstract

This study was conducted to evaluate the stable and effective isolating method of pre-antral follicles from ovary by means of mechanical or enzymatical method in mice. Mouse (ICR, 3-4 weeks old) ovarian pre-antral follicles of 70-130 microm (A: < or = 90; B: 91-110; C: 111-130 microm) in diameter were isolated by mechanical method (group I) using syringe needles or by enzymatical method (group II) using 600 IU collagenase and DNase and cultured individually in 20 microL droplet of media under mineral oil on culture dish for 8 days. On 8th day after culture, disruption rate (84.4 +/- 18.8% vs. 9.4 +/- 18.8%) was significantly higher (p < 0.05) in group II than in group I. Survival rate (88.0 +/- 28.9% vs. 0%) was significantly higher (p < 0.0000) in group I than in group II. There were no differences in the survival rate among different initial sized pre-antral follicles in group I (A: 86.7 +/- 12.5%, B: 100%, C: 69.2 +/- 30.0%, NS) or group II (A: 0%, B: 0%, C: 0%, NS), respectively. In conclusion, compared to mechanical dissection, enzymatical isolation of pre-antral follicles resulted in higher follicular disruption rate. Survival rate was not affected by different initial sizes of pre-antral follicles in mice.