不同缺氧方式和程度对大鼠不同部位一氧化氮含量的影响

目的：了解急性中、重度低压缺氧及慢性轻、中度缺氧对大鼠血液、心肌、脑皮质一氧化氮（NO）分泌的影响，进而探讨不同缺氧方式、程度时大鼠各部位NO调节的异同。方法：以硝酸还原酶法测定中、重度急性低压缺氧和慢性轻、中度低压缺氧大鼠的血液、心肌和脑皮质NO含量。结果：急性中、重度低压缺氧后即刻。大鼠的血液、心肌、脑皮质NO含量均比地面对照组显著降低（P〈0．05）；慢性轻、中度低压缺氧后，各组大鼠血液NO含量显著低于地面对照组（P〈0．05或P〈0．01）；慢性轻度低压缺氧6d组和8d组大鼠皮质NO含量显著高于地面对照组（P〈0．01），10d组皮质NO含量与地面对照组无显著性差异（P〉0．05）；慢性中度低压缺氧4d组和6d组大鼠皮质NO含量显著高于地面对照组（P〈0．01），8d组和10d组则显著低于地面对照组（P〈0．01）。结论：急、慢性轻、中、重度低压缺氧后，大鼠各部位NO水平的变化不尽相同。

Effects of acute and chronic hypobaric hypoxia of various degrees on the concentration of nitric oxide at different loci in rats

Objective: To observe effects of acute and chronic hypobaric hypoxia of various degrees on the concentration of nitric oxide(NO) at different loci in rats,and to further explore differences and similarities in the regulation of NO at various loci in rats.Methods: Concentrations of blood serum,myocardium and brain cortex were measured in rats with medium and severe acute hypobaric hypoxia and in those rats with mild and medium chronic hypobaric hypoxia.Results: The immediate NO concentrations of blood serum,myocardium and brain cortex in rats with medium and severe acute hypobaric hypoxia all dropped significantly,when compared with those of the control group(P<0.05).NO concentrations of blood serum in rats with mild and medium chronic hypobaric hypoxia were significantly lower than those of the control group(P<0.05 or P<0.01).For the 6 d and 8 d experimental groups with mild chronic hypobaric hypoxia,NO concentrations of brain cortex were significantly higher than those of the control group(P<0.01),while for the 10 d experimental group,there was no significant difference in NO concentration of brain cortex when compared with that of the control group(P<0.05).For the 4 d and 6 d experimental groups with medium chronic hypobaric hypoxia,NO concentrations of brain cortex were significantly higher than those of the control group(P<0.01),while for the 8 d and 10 d experimental groups,NO concentrations of brain cortex were significantly higher than those of the control group(P<0.01).Conclusion: Changes in concentrations of nitric oxide at different loci in rats varied,following mild,medium and severe acute and chronic hypobaric hypoxia in rats.