Taurine, or 2-aminoethane sulfonic acid, has long been known to be the major organic product formed from the breakdown of the sulfur-containing amino acids, methionine and cysteine. It is excreted as such in the urine or as bile acid conjugates in the bile. Research over the last 25 years, however, has uncovered an amazing variety of phenomena involving taurine. Despite the fact that the mechanism of action of taurine in some of these phenomena remains to be elucidated, it is clear that taurine is of far more physiological relevance than being the mere metabolic debris of sulfur amino acid catabolism. It also has numerous pharmacological actions that are beginning to be developed, as exemplified by some of the studies reported in this volume. This volume reports the proceedings of the latest of a series of international symposia, continuing on from the initial meeting held in Tucson, Arizona, in 1975. The latest symposium was the first to be held in Germany, in Cologne from August 29 through September 1, 1993. It continued the multidisciplinary approach that has been the norm for taurine symposia. We hope the publication of the proceedings will stimulate further investigations on this simple but fascinating compound.

The underlying philosophy of these two symposia on taurine remains the same as all those that have been held previously: the best way to remain current in the subject matter is to talk directly with the investigators at the forefront of the field. Thus, we brought together some 50 individuals from 11 different countries who have keen interests and active research programs in the many-faceted areas of taurine research. The meetings were held on October 8-10, 1991, in an elegant setting in a resort area at Orange Beach, Alabama, approximately 50 miles outside of Mobile on the Gulf Coast. The meetings were programmed as two separate Symposia held sequentially. The first symposia on October 8 was devoted exclusively to taurine research in the cat, primarily in the area of nutrition, and entitled "The Waltham Symposium on Taurine and Cat Nutrition". The second symposia on October 9 and 10 was open to all fields of taurine research and was entitled "International Taurine Symposium: New Dimensions on its Mechanisms of Actions". If the philosophy of these meetings was to bring both experts and novices together in a discussion and presentation of current taurine research, then the major purpose of the Proceedings is to document the current research efforts and to present an objective summary of where the taurine field stands today and where the focus will be in the future.

I was pleased and at the same time filled with some misgivings when Professors Alberto Giotti end Ryan Huxtable asked me to introduce this book. The book is the outcome of the Symposium held in Firenze-San Miniato (PI), October 6-9, 1986. The symposium was entitled "Sulfur Amino Acids, Peptides and Related Compounds" and was the 7th international symposium on taurine ßnd assooiated substances. It is always difficult to introduce, with the right brevity end emphasis, a topic which has been studied in depth by numerous experte. Nevertheless, I shall do my best to give a historical perspeotive of the subjects of the meeting which I consider to be very important for the frontiers of researoh on taurine. ~he following topios have also beoome coherent areas of study during the development of researoh on taurine: metabolism, nutrition, neurochemistry, cardiovasoular regulation. Although taurine was isolated in 1821 by ~iedman and Gmel1n, its only biochemioal role known at the time was the synthesis of bile saIte in mammalian tissue. There has been an inoreasing interest in the biologioal action of taurine from metabolio aspects to other biologioal aspects (nutrition, development, eto.). In 1975 it was first demonstrated that taurine deprivation produoed retinal degeneration in cats; more reoent studies showed that a taurine-free diet or the administration of taurine transport inhibitors caused retinal degeneration in other mammlas. More reoent studies have pointed out the role of taurine in development, and the first part of this book is dedicated to these topios

The purpose of NEURAL MECHANISM in TASTE is to emphasize physiological principles and reveal new insights of this most recent research. This book is aimed to reach scientists within the broad area of neurophysiology as well as those in other disciplines who have interests in sensory mechanisms. The focus is on two major themes--peripheral mechanisms and neural processing at the central level. Every chapter is written by an expert on the subject matter, including definitive updates on the status of each topic. This work is not only useful to researchers in taste, but also to basic and applied scientists in related fields (such as food technology), doctoral and postdoctoral students.

There can be few elements with a biochemistry as coherent as that of sulfur. This important element is crucial to myriad aspects of metabo lism, catalysis, and structure. The plurality of functions in which sulfur is involved derives squarely from the numerous oxidation states in which it may exist, some having great stability, some being capable of ready redox interconversions, and yet others having great instability. As a result, the flux of sulfur from the geosphere through the various kingdoms of life leaves few biochemical processes unaffected. Although there are large gaps in the fabric of our basic knowledge of sulfur biochemistry, it is sufficiently framed to allow a unified and organized story, a story which many of the best-known names in bio chemistry have helped to write. It has been both a task and a privilege to try and summarize this story, one that is enormous, complex, fast moving, still developing and, above all, exciting. I suppose that no mo nographer of such a vast subject could be satisfied with his efforts. It is unfortunately probable that in attempting this task I have made as many errors as a Stilton cheese has blue streaks, and as many omissions as a Swiss cheese has holes. Perfection is not to be achieved in a monograph. Inasmuch as I have succeeded, the credit belongs to those whose efforts gave us the knowledge we have. Where I have failed, the fault is only mine.

Proceedings of the International Taurine Symposium '97: Neurochemistry, Biochemistry, and Pharmacology held in Tucson, Arizona, July 15-19, 1997

Mitochondria from mammalian tissues possess an elaborate system for 2+ 2+ transporting Ca across their inner membrane which consists of Ca import, 2+ via the Ca uniporter, in response to the mitochondrial membrane 2+ + potential ?? and of Ca release by an antiport system in exchange for H + 9,23 or Na (see Fig. l) . Because the uniporter is dependent upon the external 2+ 2+ 2+ 2+ Ca concentration ([Ca ]), mitochondria accumulate Ca until the [Ca ] o o 2+ decreases to the level at which the uniporter activity balances the Ca efflux. 2+ The [Ca ] at which the uniporter and efflux activities are equal is defined o the “setpoint” andcorresponds to values between 0.3-3μM. 2+ Figure 1. The Ca transport system of the inner membrane of mammalian mitochondria. U, + 2+ + + uniporter. I, Na -independent efflux mechanism or Ca /2H exchanger. D, Na -dependent 2+ + efflux mechanism or Ca /2Na exchanger. PTP, permeability transition pore. FP, 11 flavoprotein. ?? membrane potential. ? pH gradient. Adapted from .

This volume comprises the edited proceedings of the International Taurine Sympo sium held in Osaka, Japan, in June 1995, as a Satellite Symposium of the 15th Biennial of the International Society for Neurochemistry. This Taurine Symposium was the Meeting latest in a series held since 1975 at approximately two-year intervals by an informal group of international researchers. It attracted contributions from 20 countries, ranging from Armenia via Finland and Spain to the United States. Some 121 participants attended. The Symposium was organized and chaired by Junichi Azuma, University of Osaka. Other members of the Organizing Committee in Japan consisted of Kinya Kuriyama and Masao Nakagawa, both from the Kyoto Prefectural University of Medicine, and Akemichi Baba, from Osaka University. The Committee had to contend with the disaster of the Kobe earthquake, which struck on January 21. The epicenter was only around 25 miles from the meeting site, and the quake demolished the home of one Committee member. Despite this unnaturally natural handicap, the participants experienced a superbly organized meeting, one which more than maintained the high social and scientific standards established for this series. In his Welcome Message, Dr. Azuma listed a threefold objective for the Symposium: To provide a forum for the interdisciplinary exchange of information on taurine; to give an opportunity for renewing old friendships and making new friends; and to promote coopera tion among participants from around the world.

This book is based on papers presented at a Symposium held in Seoul, Korea in 1992. The idea for the symposium developed naturally from work in which Professor Yung E Earm, at Seoul National University, had been involved both in my laboratory in Oxford and in his own laboratory in Seoul concerning the possible role of certain amino acids, like taurine that are strongly concentrated by the cells of the heart, and the relationship between such acids and membrane ionic currents. The first obvious question was whether it is possible to identify the transport mechanisms involved for taurine and whether they are electrogenic. The second question is what function could be served by such processes: does taurine play an essential role in cardiac tissue and is this important in protecting the heart from disease? With his colleagues in the Korean Physiological Society, Professor Earm set about the task of fmancing and organizing a meeting at which some of the world's leading cardiac electrophysiologists and taurine specialists could discuss these questions. The fmance was generously provided by the Dong-A Pharmaceutical Company, one of the leading scientific companies in Korea.