Lactate dehydrogenase in rabbit oocytes and eggs

It has recently been reported that the rabbit oocyte lactate dehydrogenase (LDH) isozyme pattern shifts dramatically at ovulation. We have determined that both ovarian oocytes and ovulated eggs have predominantly LDH-5 with minor amounts of LDH-4. Therefore, no change occurs at ovulation. When oocytes or eggs are not treated to remove follicle cells, all five LDH isozymes are observed. Isolated follicle cells also have five isozymes. We suggest that failure to remove follicle cells can cause altered LDH isozyme patterns and may account for conflicting results in the literature.