At the Mie International Symposium held in Japan in April 1994, leading scientists reviewed recent advances in the understanding of the contractile mechanism in smooth muscle. The present volume collects the papers presented at the symposium, summarizing the latest advances in smooth muscle function and emphasizing important components of the contraction-relaxation cycle. Topics include a discussion of the smooth muscle cell membrane, with emphasis on its ion channels; the regulation of cytosolic Ca2+ levels and the relationship to force in smooth muscle; aspects of the two key regulatory enzymes involved with myosin phosphorylation-dephosphorylation; the molecular basis for pharmacomechanical coupling in smooth muscle; developments in the basic contractile mechanisms involving the crossbridge cycle of tonic and phasic muscle; the role of myosin light chains; and many others. The approach is broad and presents contemporary opinions in pharmacology, physiology, and biochemistry as they relate to smooth muscle function. The book will appeal not only to those working in these disciplines, but to vascular clinicians, obstetric-gynecological physicians, and gastroenterologists as well.