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大鼠全身辐射损伤后小肠吸收功能变化的研究 |
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董红林 蔡军伟 吴定标
摘 要 目的：研究大鼠全身辐射损伤后小肠吸收L-酪氨酸(Tyr)的变化。方法：用在体门静脉取血法研究了6Gy 60 Coγ线全身一次照射后不同时间以及不同剂量照射后第3 d大鼠小肠吸收Tyr的变化，并测定相应的小肠上皮细胞计数、小肠粘膜钠-钾-ATP酶(Na＋-K＋-ATPase)活性以及Na+的跨膜转运。结果：6Gy γ线全身照射后第3 d出现小肠对Tyr的吸收障碍，以后很快恢复，并持续在正常水平。随着照射剂量的加大，吸收障碍加重，但3Gy以下剂量照射，则不出现Tyr的吸收障碍。小肠上皮细胞计数、Na+-K+-ATPase活性和Na＋的跨膜转运的变化与小肠吸收Tyr的变化基本一致。结论：辐射损伤后小肠对Tyr的吸收障碍与小肠上皮细胞数量减少导致的吸收面积的下降以及Na+-K+-ATPase活性下降导致的Na+跨膜转运能力的减弱有关。
主题词 辐射，电离；酪氨酸；钠(+)钾(+)转运ATP酶；大鼠
The effects of whole-body γ-irradiation on rat small intestinal absorption
DONG Hong-Lin, CAI Jun-Wei, WU Ding-Biao
Department of Pathology, Guangzhou Medical College of PLA, Guangzhou (510315)
Abstract AIM:To study L-tyrosine (Tyr) absorption of rat small intestine after 60Co whole-body γ-irradiation and its mechanisms.METHODS：Portal vein blood was obtained in vivo to study the changes of Tyr absorption of small intestine both on various days after whole-body 60Co γ-irradiation and the third day following various doses of γ-irradiation. The corresponding small intestinal epithelial cell count, mucosal Na+-K+-ATP ase activity and Na+ transport were also investigated.RESULTS：Tyr absorption decreased after exposure to 6 Gy 60Co γ-irradiation, but recovered soon afterward and remained normal during the30 days observation period. With the radiation doses increased, Tyr absorption reduced more severely. No influence on Tyr absorption was observed at doses below 3 Gy. Paralled changes were found basically between small intestinal epithelial cell count, mucosal Na+-K+-ATPase activity and Tyr absorption. CONCLUSION： Tyr absorption obstacle of rat small intestine after γ-irradiation was related to both the reduction of absorption area resulted from the decrease of epithelial cell count and the reduction of Na+transport caused by the decrease of mucosal Na+-K+-ATPase activity.
MeSH Radiation, ionizing; Tyrosine; Na(+)-K(+)-trans[1] [2] 下一页
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