Torii Y, Shikita M, Saito H, Matsuki N
Department of Chemical Pharmacology Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
J Radiat Res. 1993 Jun;34(2):164-70. doi: 10.1269/jrr.34.164.
X-irradiation-induced emesis was investigated in Suncus murinus, a house musk shrew. Whole body X-irradiation caused emesis, and the calculated ED50 value that induced emesis in 50% of animals was 429 cGy. At the irradiation dose of 800 cGy all the animals vomited 10.0 +/- 2.4 times with a latency of 20.0 +/- 2.9 min. The emetogenic effect of X-irradiation was dependent on the part of the body exposed. Abdominal X-irradiation at 1000 cGy caused emesis in all animals studied, whereas the same dose to the head had no emetogenic effect. We investigated several prophylactic methods against X-irradiation-induced emesis. Surgical vagotomy completely inhibited the emesis induced by 800 cGy X-irradiation. Emesis was also prevented by the subcutaneous administration of tropisetron (ICS 205-930, a selective serotonergic 5-HT3 receptor antagonist) with an ID50 value of 29 micrograms/kg. These results suggest that (1) suncus is a useful experimental animal for the study of radiation-induced emesis and the development of prophylactic drugs, (2) serotonin plays an important role in X-irradiation-induced emesis, and (3) X-irradiation-induced emesis is very similar to that caused by cancer chemotherapeutic agents.
在臭鼩（一种家麝鼩）身上研究了X射线照射引起的呕吐。全身X射线照射会引发呕吐，经计算，使50%的动物发生呕吐的ED50值为429厘戈瑞。在800厘戈瑞的照射剂量下，所有动物呕吐10.0±2.4次，潜伏期为20.0±2.9分钟。X射线照射的催吐作用取决于身体暴露的部位。1000厘戈瑞的腹部X射线照射使所有受试动物发生呕吐，而相同剂量照射头部则无催吐作用。我们研究了几种针对X射线照射引起呕吐的预防方法。手术切断迷走神经可完全抑制800厘戈瑞X射线照射引起的呕吐。皮下注射托烷司琼（ICS 205 - 930，一种选择性5 - 羟色胺能5 - HT3受体拮抗剂）也可预防呕吐，其ID50值为29微克/千克。这些结果表明：（1）臭鼩是研究辐射诱导呕吐及开发预防药物的有用实验动物；（2）5 - 羟色胺在X射线照射引起的呕吐中起重要作用；（3）X射线照射引起的呕吐与癌症化疗药物引起的呕吐非常相似。
