Effects of lowered temperatures and media on short-term preservation of zebu (Bos indicus) preantral ovarian follicles

The maintenance of follicle quality during the transportation of ovaries is essential for the successful cryopreservation and in vitro development of preantral follicles. The objective of this study was to evaluate the effect of cooling ovarian tissue on the conservation of zebu cow preantral follicles. Ovarian pieces were immersed in saline or coconut water (CW) solutions and maintained at 4 or 20 degreesC for 6, 12, or 18 h. Preantral follicles were evaluated by histology and transmission electron microscopy. Storage of ovarian pieces at 20 degreesC for 12 or IS h significantly reduced the percentage of morphologically normal follicles compared to controls. In contrast, conservation at 4 degreesC for up to 18 In and at 20 degreesC for up to 6 h kept the percentage of normal follicles similar to controls. However, the type of solution that the ovaries were immersed in had little effect on the results. Decreased cellular metabolism probably accounted for better preservation of preantral follicles at 4 degreesC. In conclusion, zebu cow ovaries were successfully stored at 4 degreesC for up to 18 h with no morphological damage to preantral follicles. However, at 20 degreesC, ovaries could only be stored for 6 h. (C) 2003 Elsevier Inc. All rights reserved.