Sensory Functions of the Liver--a Review

In this paper we critically review anatomic, electrophysiological, physiological, and behavioral evidence for neural receptors in the liver. Several lines of evidence suggest that the afferent innervation of the liver may be substantial, although few anatomic studies have directly addressed the question of an hepatic sensory supply. On the other hand, there is convincing functional evidence for a variety of hepatic sensory receptors. Hepatic osmo-, ion, and baroreceptors, sensitive to changes in the osmolarity and electrolyte concentrations in blood and to variations in portal venous pressure, modulate diuresis and natriuresis. Metabolic receptors, for which the adequate stimuli have not yet been specified, influence feeding behavior and gastric acid secretion in response to alterations in hepatic metabolism associated with changes in the supply of metabolic fuels. Directions for future research are suggested and general conclusions about the role of hepatic receptors in homeostasis are discussed.