Serotonin (5-HT) is one of several mediators of the signs and symptoms of carcinoid tumor. When released from this neoplasm, most of the manifestations of 5-HT are the result of activation of the 5-HT2 receptor. These manifestations are therefore likely to include which of the following effects?
High-Yield Explanation
- 5-HT2 receptors mediate smooth muscle contraction and thus cause bronchospasm and diarrhea, not constipation.- Skeletal muscle and cardiac muscle are relatively insensitive to 5-HT.- Peptic ulceration is not mediated in pa by 5-HT; the autacoid actually reduces acid secretion.