不同温度生理盐水对大鼠脊髓组织形态及一氧化氮合酶表达的影响

Effect of normal saline of different temperature on morphological changes and NOS expression of spinal cord

目的探讨不同温度生理盐水对大鼠脊髓组织形态及氧化氮合酶(nitric oxide synthase,NOS)表达的影响。方法SD大鼠96只,分成对照组、37℃组、20℃组、4℃组,每组24只。以T9为中心,打开椎管和硬脊膜。对照组不作生理盐水冲洗,其他3组分别用37、20、4℃的生理盐水缓慢冲洗。1h后关闭椎管,各组术后24h取材,称干湿质量,进行HE染色、电镜检查和β-NADPH组化染色,每组8只大鼠。结果脊髓含水量:对照组为(66.53±0.61)%,37℃组为(66.75±1.00)%改变,20℃组为(70.55±0.77)%,4℃组为(71.92±2.50)%;对照组和37℃组含水量低于20℃组和4℃组。形态学改变:对照组和37℃组无明显改变。20℃组、4℃组:光镜下主要表现为脱髓鞘和神经元肿胀,部分尼氏体消失。电镜下表现为髓鞘部分崩解,线粒体肿胀,嵴部分消失。表达NOS阳性神经元数量:对照组为(18.75±2.12)个,37℃组为(18.63±1.41)个,20℃组为(14.75±1.67)个,4℃组为(8.13±1.25)个;对照组与37℃组NOS阳性神经元数量高于20℃组和4℃组。结论20℃以下温度的生理盐水冲洗对脊髓组织有损害,脑和脊髓手术中应选择37℃的生理盐水冲洗。

Objective To investigate the effect of normal saline （NS） of different temperature on morphological changes and nitric oxide synthase （NOS） expression of spinal cord. Methods The spinal canal of 96 SD adult rats was opened at T9. which of 24 rats was flushed with 37 ℃ NS, 24 with 20 ℃ NS, 24 with 4 ℃ NS respectively, and which of 24 rats in control group received no flushing. The spinal canal was closed one hour later, and the spinal cord was taken out 24 hours later. Then the water content in spinal cord was determined by dry-wet method. The morphological changes of spinal cord were observed under light microscope and the electronic microscope. The amount of NOS-positive neuron was measured by β-NADPH histochemical methods. Results The water content in spinal cord was （66.53±0.61 ）% in control group, （66.75±1.00）% in 37 ℃ group, （70.55±0.77）% in20 ℃ group, （71.92±2.50）% in4 ℃ group. The spinal cord of control group and 37 ℃ group contained less water than that of 20 ℃ group and 4 ℃ group. There were no obvious morphological changes in the control group and 37 ℃ group. In 20 ℃ and 4 ℃ groups, the demyelination of axon, swelling of cell body and the disappearance of tigroid body were observed under light microscope, the partial disaggregation of medullary sheath, swelling of mitochondria and disappearance of mitochondria crista could be observed under electron microscope. The amount of NOS-positive neuron in spinal cord was （ 18.75±2.12）, （18.63±1.41）, （14.75±1.67）, （8.13±1.25） in control, 37 ℃, 20 ℃ and4 ℃ groups, respectively. The control group and 37 ℃ group showed more NOS-positive neuron than those of 20 ℃ group and 4 ℃ group. Conclusion NS below 20 ℃ can injury spinal cord. It is suitable to choose 37 % NS to flush brain and spinal card during operation.