吸入一氧化氮对大鼠心脏毒副作用的影响

Toxic and side effects of nitric oxide on the heart of rats

目的 观察吸入外源性一氧化氮(NO)对大鼠心脏的毒副作用。方法 将72只大鼠随机分为单纯吸氧组(G_1)(FIO_20.40)、低浓度NO吸入组(G_2)和高浓度NO吸入组(C_3),G_2和G_3组除吸氧外,分别吸入40ppm和80ppm的NO。每组分别于实验后2、8、12、24小时检测血清中肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、高铁血红蛋白(MHb)、呼出气中NO_2浓度和心肌组织含水量,并进行光镜和电镜观察。另取6只大鼠作正常对照。结果 3组心肌含水量无明显差异(P>0.05)。G_3组呼出气中NO_2浓度高于G_1和G_2组(P<0.05,P<0.02)。3组CK、CK-MB均不同程度增高,G_2组低于G_1组和G_3组(P<0.05)。G_3组MHb浓度高于G_1和G_2组。G_2组心肌组织学和超微结构的变化轻于G_1和G_3组。结论 吸入40ppm的NO对正常大鼠心脏无明显毒副作用,吸入80ppm的NO则对心肌有一定损伤。

Objective To evaluate the toxic and side effects of exogenous nitric oxide(NO) on normal rats cardiac muscles. Methods 72 rats were divided into three groups randomly , Groupl( G1 ) was on oxygen inhalation ( FiO2 0. 40) ; Group2 ( G2, n = 24) on low content of NO inhalation (40 ppm) ; Group3(G3,n =24) high content of NO inhalatiom (80 ppm). In addition, the last two groups were given oxygen inhalation. After 2,8,12 and 24 hours of the experiment, the sera creatine phosphate kinase (CK) , CK-MB and methemoglobin were determined in each group. NO, contents in expiratory air and water content in cardiac muscles were measured. Cardie muscle tissues from the three groups were examined with light and electron microscopy. Results There were no significant differences in the water content of the cardie muscle tissue among the three groups (P > 0. 05 ). The concentration of NO, in G3 was significantly higher than those in G, and G, (P < 0. 05 , P < 0. 01). Activities of CK and its isoenzyme in the three groups were increased in different degrees, but they were lower in G, than in G, and G3 ( P < 0. 05 ). The concentration of methemoglobin in G3 was higher than those in G, and G,. Histologicaly, the morphological and ultrastructural alterations of cardie muscle in G2 were lighter than those in G, and G3. Conclusions No significant toxic and side effects of nitric oxide were found on normal rats cardiac muscle tissue at 40 ppm,but 80 ppm nitric oxide inhalation was harmful to cardiac muscle tissue of rats.