高强度聚焦超声终止小鼠妊娠的实验研究

Experimental study of early mouse gestation termination induced by high intensity focused ultrasound

目的:探讨高强度聚焦超声(H IFU)终止妊娠的可能性。方法:利用H IFU治疗机(780 kHZ)6种声强各60s体内直接照射妊娠第7天小鼠胚胎,妊娠15 d时观察各组胚胎死亡率和胎盘、子宫的形态学变化。结果:对照组胚胎总死亡率为12.65%(32/253);照射组中声强3 W/cm2、6 W/cm2及≥9 W/cm2组的胚胎死亡率分别为25.00%(12/48)、72.88%(43/59)和100%(64/64、43/43、40/40、35/35)。超声照射后8 d的改变:光镜下主要为胎盘出血、变性、坏死;电镜下胎盘组织细胞坏死呈致密团块状,子宫改变轻微。变化随剂量的增加而明显。结论:胎盘较子宫对H IFU更敏感,更易受损,H IFU抗早孕具有潜在的可行性,值得进一步研究。

Objective： To investigate the availability of early pregnancy termination with high intensity focused ultrasound （HIFU）. Methods： The implantation sites of left uterus of 7th day mouse embryos were exposured with an intensity of 3 W/cm^2× 60 s, 6 W/cm^2×60 s, 9 W/cm^2×60 s, 12 W/cm^2×60 s, 15 W/cm^2×60 s and 18 W/cm^2×60 s. At same time, the embryos of fight uterus belonged to the control group. At 15th day of gestation , the animals were sacrificed. Embryonic mortality and morphology changes of placentas and uteruses were observed. Results： It was found that total embryonic mortality of control group was 12.65 % （ 32/253 ） and those of experimental group were 25.00 % （12/48）, 72.88 % （ 43/59 ） and 100% （ 64/64, 43/43, 49/40, 35/35 ） respectly with an intensity of 3 W/cm^2, 6 W/cm^2 and≥9 W/cm^2. Under optical microscope, necrosis and hemorrhage were observed in placenta on 8th day after irradiating. Under electron microscope, the cells of placenta were found to have lost normal stmctures and there was no obvious change in endometrial and vascula endothelial cells. Conclusion： The result proves that the placenta are more sensitive and injured to HIFU than uterus , that it is feasible for early pregnancy termination of mouse with HIFU.