In this population of oocytes, okadaic acid, which is a potent inhibitor of protein phosphatases and accelerates GVBD in cattle oocytes, did not induce GVBD. There are a few reports regarding the quality of meiotically arrested oocytes and their subsequent ability for maturation, fertilization, and development in vitro. In these previously reported studies, meiotic arrest was induced using a range of chemical inhibitors including cycloheximide, 6-dimethylaminopurine, or vanadate. Following these treatments, a significantly lower frequency of development to the blastocyst stage was obtained than in control oocytes matured directly after aspiration. flovent inhaler
During the studies reported here, it was observed that when oocytes are cultured either attached to part of the follicle wall or inside hemisections of follicles, the volume of culture medium is critical. When a small volume was used, changes in pH appeared to adversely affect the oocytes; although the oocytes remained at the GV stage, an abnormal chromatin morphology was observed. In contrast, when a large volume of culture medium was used, a lower percentage of oocytes remained arrested at the GV stage. This may reflect the dilution of one or more inhibitory factors produced by the follicular components.