THE FUNCTION OF THE ABDOMINAL CHEMORECEPTORS OF THE RAT AND MOUSE

Abstract

Nitrogen inhalation or intravenous cyanide has produced slight respiratory reflexes in each of 12 mice in which chemoreceptors in the neck and thorax had been eliminated. In the rat with known chemoreceptors eliminated, the respiratory response has been much more variable, but with cyanide a clear-cut vascular response was usually obtained. The responses following intravenous cyanide disappeared after section of the abdominal vagi and the splanchnic nerves, which previously have been shown to be the pathways through which sensory fibers reach the abdominal epithelioid bodies of the mouse and rat. Further localization of the origin of a chemoreceptor response from structures within the abdomen was obtained by local application of cyanide to the abdominal, bodies; the reflexes so obtained were predominant vasopressor and disappeared following combined abdominal, vagal and splanchnic nerve section. The abdominal epithelioid bodies of the mouse and rat appear, therefore, to be chemoreceptors influencing primarily, at least in the rat, the cardiovascular system.