加速度重复作用下咬肌内皮素和一氧化氮的测定分析

The effects of repeated +Gz forces on the levels of endothelin and nitric oxide in masseter muscles

目的：观察加速度（＋Ｇｚ）重复作用对咬肌内皮素（ＥＴ）和一氧化氮（ＮＯ）含量的影响。方法：体重为２００～２５０ｇ雄性Ｗｉｓｔａｒ大鼠１２只随机分成Ａ组和Ｂ组，各６只。 Ａ组用特制的固定装置固定５ｍｉｎ，Ｂ组固定在动物离心机的转臂上，头朝向轴心，＋１０Ｇｚ峰值持续时间为３０ｓ，Ｇ值增长率约为 ０．５ Ｇ／ｓ，间隔十１ Ｇｚ６０ｓ，连续５次／ｄ，４ｄ／周，共３周。离心后取大鼠咬肌和血浆测定内皮素和一氧化氮含量。结果：与Ａ组相比，Ｂ组咬肌组织中内皮素含量增高而一氧化氮含量未见变化，Ｂ组血浆中内皮素和一氧化氮含量均未见变化。结论：加速度可引起咬肌局部血流调节因子内皮素和一氧化氮比例失调，在咬肌发生病理改变过程中起一定作用。

Objective: To study the effects of repeated +Gz forces on the levels of endothelin(ET) and nitric oxide(NO) in the plasma and masseter musscles. Methods: 12 male Wistar rats were randomly divided into 2 groups. The rats in group A were borne +1Gz for 5 minutes. Those in group B were repeatedly exposed +10Gz (each for 30s, onset rate was 0.5 G/s, 5 times/d with + 1Gz 1 minute intervals, 4 d/wk, 3 weeks in total). ET and NO in masseter muscles and blood plasma were measured with radio-immunological kit and Griess method respectively after the three-week-treatment. Results: ET(ng/L) in masseter muscles in group A and group B was 152.79 ± 20.48 and 215.55 ± 54.22 (P<0.05), that in plasma 235.97± 20.61 and 238. 40 ± 21.97(P>0. 05); NO(μmol/L) In masseter muscles in group A and group B was 1. 26 ± 0.53 and 1. 05±0. 15(p>0. 05), that in plasma 68. 66± 54. 22 and 45. 13± 29. 27 (P >0. 05), respectively. Conclusion: Repeated +Gz stress may disorder the ratio of ET and NO. This imbalance may be one of the causes which lead to pathology changes in masseter musscles.