1. G. Watanabe, Y. Saito, P. Madaule, T. Ishizaki, K. Fujisawa, N. Morii, A. Kakizuka, S. Narumiya, Department of Pharmacology, Kyoto University Faculty of Medicine, Kyoto 606, Japan.
2. H. Mukai and Y. Ono, Department of Biology, Faculty of Science, Kobe University, Kobe 657, Japan.