Hormones and bioactive substances that affect peripheral taste sensitivity

Taste receptor cells in taste buds detect chemical compounds in foods and drinks and transmit these signals through gustatory nerve fibers to the central nervous system. Sensory signals of taste are essential for animal feeding behavior; animals prefer sweet taste and avoid bitter and sour tastes. Recent studies have demonstrated that the sensitivity of taste receptor cells to tastants is not constant but is subject to regulation by hormones and bioactive substances, such as leptin and endocannabi-noids. Leptin selectively suppresses sweet taste sensitivity. In contrast, endocannabinoids selectively enhance sweet taste sensitivity. Both types of signaling molecules act at their respective receptors in sweet-sensitive taste cells. In addition, glucagon-like peptide-1 (GLP-1), glucagon, oxytocin, insulin, cholecystokinin, neuropeptide Y, and vasoactive intestinal peptide (VIP) have been implicated in the regulation of peripheral taste sensitivity. In this review, the hormones and bioactive substances that affect peripheral taste sensitivity are summarized. Regulation of peripheral taste sensitivity by hormones and bioactive substances may play an important role in the control of feeding behavior and maintenance of energy, ion, and amino acid homeostasis in animals.