The dynamic state of developments within the field of the vasoactive polypeptides is reflected in the continuous series of publications appearing on this topic Thus, the proposal to con­ o vene another symposium only two years after the 1969 Fiesole Symposium (Plenum Press, 1970) was received enthusiastically and with high expectation. Enthusiasm was based, undoubtedly, in part on meeting together once again in the very pleasant surroundings of Florence with most gracious and enchanting hosts. The 25th International Congress on Physiological Sciences held in Munich the following week also provided the impetus for the organization of this satellite symposium on vasopeptides. However, the accelerated pace of research in the "kinin" field was the major motivating force for the symposium. It was felt necessary to inform each other of the many advances that were taking place in the varied aspects of this specialized but impor­ tant field o The role of kinins in both physicologic and pathologic processes still remains to be elucidated definitively. Thus, these proceedings contain new and unpublished informa­ tion on the chemistry, biochemistry, physicology, pharmacology, as well as pathophysiology of vasopeptides. Recent data on &tructure­ activity relationships of kinin analogues are complemented by a description of radioimmunoassay techniques for kinins, and studies on the site of synthesis of substrates for kinin-forming enzymes.