The Study Of A New Vomit Model

Chemotherapy and radiotherapy are associated with vomit as a common adverse reaction in the treatment of cancer. It is of great value to screen an animal model whose vomiting behavior resembles that of human being in studying vomit mechanism. We established an ideal vomit model in minks firstly in the world. Not only getting over rats and mouse without vomit behavior, dogs, cats and pigeons have vomit behavior, lack of nausea and retching, but also it is inexpensive and can be raised easily, not influenced by the environment largely. Using the mink vomit model, we investigated the emetic effect of cisplatin, copper sulfate, apomorphine, raw pinellia, X-ray and rotation, in addition, we examined the effects and mechanisms of antiemetic drugs, 5-HT3 receptor antagonist and pinellia.The follows are the results:1 Cisplatin (7.5mg kg-1, ip) evoked emesis by stimulating the release of DA and 5-HT in central and peripheral nervous system. The number of nausea, retching and emesis are 91.5 and 12 (P<0.01) .2 Copper sulfate (40mg kg-1, ig) induced emesis by stimulating the mucosa of gastrointestinal tract. The number of nausea, retching and emesis are 29and 8.7 (P<0.01) .3 Apomorphine evoked emesis by agitating dopamine receptors of CTZ. The number retching and emesis are 28.5 5.3 (P<0.01) .4 Raw pinellia can also induce emesis in minks. The number of retching and emesis are 78.3 and 13.3 (P<0.01) .5 X-ray can also induce emesis in minks. The number of retching and emesis are 19 and 10 (P<0.01) .6 Rotation can also induce emesis in minks.The number of retching and emesis are 29and 6 (P<0.01) .7 Antiemetic drugs such as metoclopramide (dopamine antagonist), ondansetron ( antagonist), pinellia can obviously inhibited the emesis induced by cisplatin, apomorphine and rotation. The latency of vomit is prolonged noticeably and the number of retching and emesis are largely reduced.8 In cisplatin group,the assay of distribution of 5-HT was performed by immunohitologic method. The results showed that 5-HTa receptors stimulate abdominal vagal afferent neurons which may be an important mechanism involved in vomiting.The results suggested that as a new vomit model, minks may be of great value not only hi studying vomit mechanism and screening new antiemetic drugs, but in the research of radiation, aeromedicine and motion sickness.Postgraduate: Fang Xuan (Pharmacology) Directed by: Prof. Yue Wang...