Martin C, Roman V, Agay D, Fatôme M
Département de Radiobiologie, Centre de Recherches du Service de Santé des Armées Emile Parde, La Tronche, France.
Radiat Res. 1998 Jun;149(6):631-6.
The anti-emetic efficiency of orally administered ondansetron and granisetron has been tested in macaques exposed to a mixed y and neutron radiation (6 Gy) with a high neutron/gamma-ray ratio. Our experiments reveal that a single delivery of ondansetron (1 or 2 mg kg(-1)) or of granisetron (0.25 mg kg(-1)) 45-90 min before irradiation or 35-45 min after irradiation was not totally effective. Conversely, the delivery of two doses with the same delay prior to and after exposure led to a complete prevention of vomiting and retching. These observations can be explained by the dual mechanism of radiation-induced emesis: an early peripheral mechanism and a later central mechanism. Two deliveries of 5-HT3 receptor antagonists seem to disrupt serotonergic transmission at the brain stem structures and to affect the peripheral release of serotonin from the gut, thus completely preventing radiation-induced vomiting. This study confirms that the 5-HT3-dependent mechanisms that mediate emesis are similar for both neutron and gamma radiation.
已在暴露于高中子/γ射线比的混合γ和中子辐射（6 Gy）的猕猴中测试了口服昂丹司琼和格拉司琼的止吐效果。我们的实验表明，在照射前45 - 90分钟或照射后35 - 45分钟单次给予昂丹司琼（1或2 mg kg⁻¹）或格拉司琼（0.25 mg kg⁻¹）并不完全有效。相反，在暴露前后相同延迟时间给予两剂可完全预防呕吐和干呕。这些观察结果可以通过辐射诱发呕吐的双重机制来解释：早期的外周机制和后期的中枢机制。两次给予5 - HT3受体拮抗剂似乎会破坏脑干结构处的5 - 羟色胺能传递，并影响肠道中5 - 羟色胺的外周释放，从而完全预防辐射诱发的呕吐。这项研究证实，介导呕吐的5 - HT3依赖性机制在中子辐射和γ辐射中相似。
