Serotonin Receptors

Since the middle of the nineteenth century, physiologists have been aware of an endogenous vasoconstrictor substance. Often referred to as “vasotonin,” the factor was present in the serum of clotted blood. (1948 ) succeeded in isolating the compound and named it “serotonin.” The chemical structure was soon found to be 5-hydroxytryptamine (5-HT). Simultaneously and independently, Italian scientists were studying a substance found in high concentrations in enterochromaffin cells of the intestinal mucosa that was also eventually found to be 5-HT (Erpsamer and Asero, 1952 ). The synthetic production of 5-HT (Hamlin and Fischer, 1951 ) led to an explosion of research into the physiologic function of this compound.