INTERACTION OF NERVOUS AND LOCAL CONTROL OF THE INTESTINAL CIRCULATION

Abstract

Publisher Summary This chapter describes the interaction of local and nervous mechanisms in the intestinal microcirculation of isolated perfused gut loops. The intestinal circulation is regulated by three different types of physiological mechanisms: circulating hormones, nervous mechanisms, and local mechanisms intrinsic to the gut itself. The investigations of nervous mechanisms in the intestinal circulation have a long history, which established that the gut, like many other organs, is capable of autoregulating its blood flow. However, the interactions of local and nervous mechanisms, especially at the microvascular level, have received little attention. One reason for this is the disparate experimental approaches for studying the two types of mechanisms. Reflex control is generally investigated in conscious or anesthetized animals, but the studies of autoregulation require the isolated, perfused organ approach. The results obtained in the two kinds of studies are often difficult to compare and in many cases, they are contradictory. Both approaches are essential. The perfused organ yields more direct evidence of local control or nervous effects at the microvascular level, while studies in intact animals delineate the relative roles played by local and nervous mechanisms in various physiological settings.