Since the discovery of kallikrein by the Munich surgeon E.K. Frey (1925) and the elucidation by E. Werle (1936) of the basic biochemical mechanisms which lead to kinin liberation from kininogens by kallikreins or to kinin degradation by kininases, this KKKK field has become a promising subject for basic and applied research. The 'Munich kid', the kallikrein, was found to be involved in important mechanisms of the organism and has attracted special medical interest. The International Conference 'Kinin 81 Munich', held November 2nd - 5th, 1981, covered all aspects of the KKKK systems and related fields. The recent progress was presented in 265 contributions, 93 lectures and 172 posters, and discussed by nearly 400 scientists from 27 countries. This volume contains chiefly the lectures presented during the Conference.