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