Morphological study of fully and partially isolated early human follicles

Objective: To compare the development of fully and partially isolated human follicles by using various culture systems. Design: Human ovarian material was incubated with collagenase and deoxyribonuclease. Fully and partially isolated follicles (30-50 μm) were dissected and studied under light and electron microscopy. The follicles were then cultured on and within various matrices. Fully isolated follicles were also cocultured with stromal cells. Setting: Rabin Medical Center, a major care and referral center. Patient(s): Women undergoing laparoscopy. Intervention(s): None. Main Outcome Measure(s): Microscopy studies, follicular measurements. Result(s): Electron microscopy studies revealed an excess of lipid droplets in the granulosa cells of freshly isolated follicles. An increase in follicular size and granulosa cell number was observed only in the fully isolated follicles cultured within collagen gels for 24 hours. Most of the partially isolated follicles detached from the collagen gels. When cultured on collagen, extracellular matrix, and poly-L-lysine, both the fully and the partially isolated follicles deteriorated within the first 24 hours; coculture with stromal cells had no beneficial effect. Conclusion(s): The excess in lipid droplets in granulosa cells of isolated follicles might suggest that the isolation process does not yield completely healthy follicles. However, despite this finding, our studies show that fully isolated follicles, but not partially isolated follicles, can grow within, but not on, a culture matrix.