抄録
The mammalian liver is not only a metabolic, storage, or clearance organ but also contains many receptors, now shown to include osmoreceptors, baroreceptors, ionic receptors, and glucose receptors.In this paper I review physiological and pathophysiological roles of hepatoportal Na-sensitive mechanism. Na consumed orally is absorbed from the intestine into the blood and circulates in the hepatic vasculature first, then go into the systemic circulation. The hepatoportal Na-sensitive mechanism is triggered by the increase in portal venous Na concentration in advance of changes in systemic blood Na concentration and reflexively control Na appetite, Na absorption, and Na excretion. Furthermore, the hepatic blood flow is -25% of the systemic blood flow. Thus the hepatoportal Na-sensitive mechanism can detect amplified Na changes, whereas once absorbed Na enters into the systemic circulation, it is diluted by five times. Therefore, the hepatoportal Na-sensitive mechanism may predict changes in systemic blood Na concentration on the basis of amplified changes in portal Na concentration, then control body fluid Na homeostasis in a prospective manner.
