广西医学

目的观察硝酸甘油或硝普钠联合艾司洛尔控制性降压（CH）对兔脑组织损伤的影响。方法将18只新西兰兔随机分为对照组、硝酸甘油+艾司洛尔组、硝普钠+艾司洛尔组，每组6只。硝酸甘油+艾司洛尔组以0.5 μg/（kg·min）硝酸甘油及2.5 μg/（kg·min）艾司洛尔为初始剂量降压，硝普钠+艾司洛尔组以0.5 μg/（kg·min）硝普钠及2.5 μg/（kg·min）艾司洛尔为初始剂量降压，使股动脉平均动脉压（MAP）降至基础值的（70±10）%，维持1 h；对照组持续泵注20 mL/h生理盐水，使股动脉MAP维持在基础值的±10%范围内。比较各组兔CH前后的股动脉MAP，采用ELISA检测各组兔CH前后血清S100β蛋白水平，采用TUNEL染色检测各组兔海马CA1区神经元细胞凋亡率，通过透射电镜观察各组兔海马CA1区神经元细胞超微结构变化情况。结果 CH 1 h后，硝酸甘油+艾司洛尔组与硝普钠+艾司洛尔组兔股动脉MAP低于对照组（P<0.05），而硝酸甘油+艾司洛尔组与硝普钠+艾司洛尔组兔股动脉MAP差异无统计学意义（P>0.05）。3组兔CH前后血清S100β蛋白水平差异无统计学意义（P>0.05）；CH 1 h后，3组兔的血清S100β蛋白水平差异无统计学意义（P>0.05）。CH 1 h后，3组兔海马CA1区神经元细胞凋亡率差异无统计学意义（P>0.05），神经元细胞结构完整、线粒体嵴膜完整。结论以硝酸甘油或硝普钠联合艾司洛尔进行控制性降压，可有效降低兔股动脉MAP且对兔脑组织无明显损伤。

Objective To observe the effects of controlled hypotension (CH) induced by nitroglycerin or sodium nitroprusside combined with esmolol on cerebral injury in rabbits. Methods A total of 18 New Zealand rabbits were randomly divided into three groups, with 6 rabbits in each group: control group, nitroglycerin+esmolol group, and sodium nitroprusside+esmolol group. In the nitroglycerin+esmolol group, hypotension was induced with an initial dose of 0.5 μg/(kg·min) nitroglycerin and 2.5 μg/(kg·min) esmolol, whereas in the sodium nitroprusside+esmolol group, hypotension was induced with an initial dose of 0.5 μg/(kg·min) sodium nitroprusside and 2.5 μg/(kg·min) esmolol, reducing femoral artery mean arterial pressure (MAP) to (70±10)% of baseline for maintaining this level for 1 hour. The control group received a continuous infusion of 20 mL/h normal saline to maintain femoral artery MAP within ±10% of baseline. Femoral artery MAP was compared between rabbits in various groups before and after CH. Serum level of S100β protein in various groups was measured by ELISA before and after CH. The neuronal apoptosis rate of rabbits in various groups in hippocampal CA1 region was evaluated by TUNEL staining, and ultrastructural changes of rabbits in various groups in hippocampal CA1 neurons were observed by transmission electron microscopy. Results After 1 hour of CH, femoral artery MAP in both the nitroglycerin+esmolol group and the sodium nitroprusside+esmolol group was lower than that in the control group (P<0.05), with no statistically significant difference between the nitroglycerin+esmolol group and the sodium nitroprusside+esmolol group (P>0.05). There was no statistically significant difference in serum S100β protein level between the three groups before or after CH (P>0.05), nor between the groups at 1 hour after CH (P>0.05). After 1 hour of CH, no statistically significant difference in the neuronal apoptosis rate in hippocampal CA1 region was observed between the three groups (P>0.05), and neuronal structures remained intact with well-preserved mitochondrial cristae membranes. Conclusion Controlled hypotension induced by either nitroglycerin or sodium nitroprusside combined with esmolol can effectively reduce femoral artery MAP in rabbits without causing significant injury in cerebral tissue.