A single electrical pulse induces only one Ca2+ transient, and this transient is sufficient to induce CG exocytosis and resumption of oocyte meiosis in pig oocytes. When A23187 was used in the present study, we also observed one Ca2+ transient in the pig oocytes. From this, it seems that there is similarity between the two stimulators. However, some differences were observed between the two artificial stimulators. One is that electrically activated pig oocytes showed the same penetrability by spermatozoa after in vitro insemination as that in control oocytes, but A23187-treated oocytes showed significantly lower penetrability in a concentration-dependent manner (Tables 2 and 3). Buy Asthma Inhalers Online
It is possible that the CG exocytosis induced by electrical pulse did not activate CG enzymes, or destroyed the bioactivity of CG materials, because we observed that the same degree of CG exocytosis was induced by A23187 and electrical pulse in our other experiment. However, a previous study in bovine oocytes indicated that electrically pulsed oocytes did resist sperm penetration. Why there are differences between these two species in results from electrical activation of oocytes is unclear.