Membrane potential measurements in human oocytes.

Both maturation and fertilization of oocytes involve changes within the cell membrane as also in other cell structures. One method of documenting this phenomenon is the electrophysiological measurement of membrane potential (MP). Changes of MPs occurring coincidentally with the development of oocytes have been published previously for intervertebrates and vertebrates. In the present investigation MPs were measured in human oocytes at different stages of development. This was to prove whether the data published for animal models are also relevant in man. MPs were obtained from oocytes recovered for in vitro fertilization (IVF). This procedure produces not only the desired normal fertilized oocytes, but also immature cells, oocytes with failure of fertilization and pathologically fertilized oocytes. The results obtained show a good correlation of MP-changes during development and after fertilization with data published previously from a variety of species. In mouse and human oocytes, even absolute MP-values show a good correlation.