SEROTONIN AND VASOCONSTRICTOR SYNERGISM

Contractile synergism between serotonin (5-hydroxytryptamine, 5-HT) an d other vasoconstrictor substances has been observed in a number of pe ripheral and cerebrovascular blood vessels. This phenomenon may play a n important role in certain pathological states such as hypertension, peripheral vascular disease, and coronary spasm. In the present review , we summarize studies on the synergism between serotonin and other va soconstrictor agents and focus on a recently described type of vasocon strictor synergism in which precontraction with a non-5-HT receptor ag onist yields an enhanced contractile response to serotonin which is me diated by previously inactive or ''silent'' 5-HT receptor subtypes.