Tyers M B, Bunce K T, Humphrey P P
Glaxo Group Research Limited, Ware, Hertfordshire, U.K.
Eur J Cancer Clin Oncol. 1989;25 Suppl 1:S15-9.
Three main types of 5-HT (serotonin) receptor have been recognised. The 5-HT3 receptor is located on neuronal tissues in the peripheral and central nervous systems. Ondansetron is a highly selective and potent antagonist for this receptor type. The severe nausea and vomiting caused by cytotoxic agents and radiotherapy can be reduced by metoclopramide treatment, but extrapyramidal side effects are common due to antagonism of dopamine receptors. Ondansetron has been found to significantly delay the onset of emesis, and reduce the number of retches and vomits in ferrets receiving cisplatin, cyclophosphamide, or radiation, at much lower doses than metoclopramide and without the associated side effects. Experiments to define the site of action of ondansetron suggest that at least part of its antiemetic action is in the area postrema, though a peripheral site of action in the upper gastrointestinal tract is also a possibility.
已识别出三种主要类型的5-羟色胺（5-HT，血清素）受体。5-HT3受体位于外周和中枢神经系统的神经组织上。昂丹司琼是该受体类型的高度选择性和强效拮抗剂。细胞毒性药物和放射治疗引起的严重恶心和呕吐可通过甲氧氯普胺治疗减轻，但由于多巴胺受体拮抗作用，锥体外系副作用很常见。已发现昂丹司琼能显著延迟呕吐发作，并减少接受顺铂、环磷酰胺或放疗的雪貂的干呕和呕吐次数，其剂量远低于甲氧氯普胺，且无相关副作用。确定昂丹司琼作用部位的实验表明，其至少部分止吐作用位于最后区，不过在上消化道也可能存在外周作用部位。
