Estimation of 6-Phosphogluconate Dehydrogenase (6PGD) Activity and Development of Fresh Bovine Embryos Derived from in Vitro Fertilization

To survey the relationship between metabolic activity and developmental ability of bovine embryos derived from in vitro fertilization, we modified an enzymatic cycling method in the present study. We measured 6-phosphogluconate dehydrogenase activity (6P)GD) in single bovine embryos derived from in vitro fertilization in preimplantation stages and checked their developmental ability. When measured by adding 6-phosphogluconate as a substrate, 6PGD activities were 62.8±9.2, 77.4±3.3,103.4±6.8, 96.2+0.5 and 120.6±3.4 (X109 mol/embryo/h) in the 2-cell, 4-cell, 8-cell, morula and blastocyst stage embryos, respectively, indicating significant differences between groups at the 2- or 4-cell stages and blastocyst stage (P<0.05). In all cell stage embryos, the level of 6PGD activity increased by adding the substrate. When subsequent development was examined after measurement of 2-cell, 4-cell, 8-cell and morula stage embryos, the developmental rate to blastocyst stage ranged from 18.8 to 61.0% and did not vary among the different stages.