^(99)Tc^m-MIBI作为再灌注损伤示踪剂的初步实验研究

99 Tc m MIBI as a tracer for reperfusion injury following limb ischemia reperfusion

目的探讨９９Ｔｃｍ甲氧基异丁基异腈（ＭＩＢＩ）作为再灌注损伤示踪剂的可能性。方法７５只ＳＤ大鼠和６只新西兰兔分假手术对照和再灌注损伤（ＲＰＩ）２组。ＲＰＩ组结扎主动脉和下腔静脉，致双下肢缺血１５ｈ。测量再灌注过程中心率、动脉压、血气含量和脏器组织９９ＴｃｍＭＩＢＩ和２０１Ｔｌ摄取和残留。分析ＯＨ－自由基清除剂、ＯＨ－生成系统和阴离子化合物对脏器组织摄取９９ＴｃｍＭＩＢＩ的影响。结果ＲＰＩ和假手术组的心率、血压和血气含量无明显差别。再灌注时，肝、肺、心、肾和下肢缺血后骨骼肌早期摄取９９ＴｃｍＭＩＢＩ呈两次增加（再灌注后第１和第３０ｍｉｎ）。与对照组比较，再灌注３０ｍｉｎ心、肺、肾和下肢缺血后骨骼肌９９ＴｃｍＭＩＢＩ摄取分别平均增加了１４１％、８５％、８６％和１７５％；相反，相应脏器组织２０１Ｔｌ摄取平均减少了６６％、３１％、４４％和８％。正常骨骼肌摄取９９ＴｃｍＭＩＢＩ减少１９％，而２０１Ｔｌ摄取增加３３％。氧自由基和抗氧自由基仅能部分影响脏器组织摄取９９ＴｃｍＭＩＢＩ，而阴离子化合物可明显影响９９ＴｃｍＭＩＢＩ摄取。ＲＰＩ组织残留９９ＴｃｍＭＩＢＩ比对照组减低。ＲＰＩ的９９ＴｃｍＭＩＢ?

Objective Our study was designed to demonstrate the possibility of using 99 Tc m MIBI as a tracer for reperfusion injury Methods 75 SD rats and 6 New Zealand rabbits were divided into the control and reperfusion injury (RPI) groups The RPI was achieved by ischemia reperfusion treatment of the lower limbs The early uptake and retention of 99 Tc m MIBI or 201 Tl in organs or tissues were counted 10 minutes and 1 5 hours after injection respectively during reperfusion The effect of anion (tetraphenyl borate), OH - system (H 2O 2 plus Cu 2+ ) and OH - scanvengers (mannitol plus vitamin C) on uptake of 99 Tc m MIBI was also analysed Results There was no difference between control and RPI rats in hemodynamics and arterial blood gases In RPI groups, there were two peaks of uptake of 99 Tc m MIBI in heart, lung, kidney and muscles of lower limbs increasing by 141%, 85%, 86% and 175%, while that of 201 Tl decreased by 66%, 31%, 44% and 8%, respectively; and in muscles of upper limbs, however, the uptake of 99 Tc m MIBI decreased by 19% and 201 Tl increased by 33% The OH - and its scanvenger only partially but anion significantly increased the early uptake of 99 [KG*2/3]Tc m MIBI comparing with control groups In heart and muscles of upper limbs, the residual activity of 99 Tc m MIBI was significantly lower (43% and 75% of the early uptake in RPI groups, 103% and 147% of the early uptake in control groups) Conclusions Though the mechanism of the variation of uptake and retention of 99 Tc m MIBI in organs or tissues observed after the lower limb ischemia reperfusion treatment is not clear now, 99 [KG*2/3]Tc m MIBI may be a useful tracer for reperfusion injury in vivo and in vitro