Experiments were conducted to examine the effect on in vitro maturation of bovine oocytes and subsequent developmental capacity of embryos of several Japanese Kampo Medicines (JKMs), which have been reported to be effective in the treatment for reproductive failure in both women and rats. In the first experiment, the most effective JKM and its optimal concentration were determined by adding JKMs to bovine calf serum (CS)-free TCM 199 medium and examining developmental capacities of oocytes after fertilization in vitro. Similarly, in the second experiment, the comparison of the effect of the most effective JKM on in vitro maturation with that of CS was carried out. The morphological characteristics of oocytes after in vitro maturation were also examined using transmission electron microscopy. Keishibukuryogan (TJ25) was found to be the most effective JKM and 100 mu g/ml was optimal level for all JKMs, though no blastocysts were obtained. The additon of CS to maturation medium still induced significantly (P<0.05) higher rates of development to morulae and blastocysts compared with that of TJ25. Surprisingly, when TJ25 was added to the medium in combination with CS, neither morulae nor blastocysts were obtained Ultrastructures of the oocytes treated with JKMs were characterized by aspects such as elongated cumulus cells and uniformly distributed cortical granules. lit conclusion, JKM (TJ25) showed certain positive effect on maturation of bovine oocytes in vitro, However much still remains at large about the mechanism.
