【摘要】 致死剂量X线照射前给小鼠腹腔注射5-羟色胺(5-HT)可明显提高小鼠的30天存活率,其ED50(30)为11.2±2.21毫克/公斤体重。5-HT(10毫克/公斤体重)和2,2-二甲基四氢噻唑盐酸盐(DMTD)复方使用时,可显著提高对大、小鼠的防护效果。5-HT使动物的氧耗量急剧下降,而DMTD则无此作用。N-异丙基异菸肼(IIH)在照前24小时给药无任何防护作用。用IIH与5-HT复方时,防护效应反而减弱。DMTD可使受致死剂量γ射线照后第8天大鼠血和脾组织中的5-HT水平提高,并与血小板数有一定的平行关系。5-HT本身的注入对照射动物血和脾组织中5-HT水平的影响不如DMTD的注入明显。更多还原

【Abstract】 5-Hydroxytryptamine ( 5-HT ) injected i.p. into mice before a lethal dose of X-ray irradiation, exhibited a good radioprotective activity. The ED50(30) of 5-HT was 11.2±2.21mg/kg.In mice and rats, a composite of 5-HT ( 10mg/kg ) and 2, 2-dimethylth-iazolidine hydrochloride ( DMTD, 125mg/kg)exhibited a more marked radio-protective activity. The dose-reduction factor was 1.6.The oxygen consumption of mice decreased rapidly after administration of 5-HT, while it remained unchanged after injection of DMTD.When iproniazid(IIH)wasinjected 24 hours before irradiation, no protective action could be observed. In addition, the protective effect of 5-HT decreased in the presence of IIH.The level of 5-HT in blood and spleen of rats treated with DMTD on 8th day after exposure to γ-ray was higher and the increase of 5-HT level was parallel to the blood platelet count. Less effect was found on the 5-HT level in blood and spleen when 5-HT itself was given to animals before irradiation.更多还原