The Sapporo International Symposium on "Recent Advances in Nitric Oxide Research" was held in Sapporo, Japan, in 1997, following the Fifth International Meeting on the Biology of Nitric Oxide in Kyoto, Japan, organized by Dr. Salvador Moncada, Dr. Noboru Toda, and Dr. Hiroshi Maeda. The field of nitric oxide research continues to expand rapidly, and our understanding of the physiological and pathophysiological roles of NO has increased greatly. The Kyoto Meeting was stimulating and informative, providing impetus for the Sapporo Symposium, which I had the great honor to organize. To communicate the information from these events, Dr. Ichiro Sakuma and I decided to publish this book. The contents of its chapters were contributed by the participants who were active at the Sapporo symposium and cover the majority of the presentations made during that symposium. Dr. Csaba Szabo of Children's Hospital Medical Center in Cincinnati (U. S. A. ) reviews the roles of peroxynitrite and poly(ADP-ribose)synthetase in shock, inflammation, and reperfusion injury, and Dr. David A. Geller and his colleagues of the University of Pittsburgh (U. S. A. ) review the regulation and function of NO in the liver. As contributions from the Hokkaido University School of Medicine (Sapporo), Dr. Hiroko Togashi and colleagues present their data on transient cerebral ischemia and NO production, Dr.