The Resistance Arteries is focused on the general issue of the regulatory pathways in resistance arteries and comprises a selection of timely overviews and up-to-date research studies presented at the 4th International Symposium on Resistance Arteries. These small vessels act as major controllers of blood pressure, blood flow, and its distribution, and are involved in a variety of pathological conditions. Vascular diameter is influenced by a host of factors, some extrinsic to the smooth musc1e cells and some intrinsic. One will find contributions in nearly all of the five themes by which the book is organized; these address intra-and extracellular interactions, and membrane receptor pathways using vascular beds as diverse as the brain, he art, lung, kidney, and skin. Basic physiological studies are inc1uded; these examine: growth fac­ tors, vasoactive endothelium-derived nitric oxide, the impacts of flow and stretch, myogenic mechanisms, calcium regulation by protein kinase C, and signal transduction pathways of the vascular smooth musc1e cell membrane receptors. Not only are tissues from appropriate animal models exploited in most of these reports, but many reflect the current increase in the use of human tissue to elucidate vascular alterations of function and morphology in hypertension, atherosclerosis, and ischemia. Noteworthy among the many techniques used are: membrane permeabilization with toxins, fura-2 for calcium determination, single cell electrophysiology, and the application of confocal microscopy to isolated, living vessels.