N_ω-硝基-L-精氨酸和谷氨酸单氨钠对高血压大鼠心率、血压及脑卒中的影响

Influence of N_ω-nitro-L-arginine and L-glutamic acid monoammonium salt on heart rate, blood pressure and stroke in hypertensive rats

目的:观察长期使用Nω-硝基-L-精氨酸(L-NNA)和谷氨酸单氨钠(MSG)后高血压大鼠心率、血压的变化,以及脑卒中发生的情况。方法:每日给SD大鼠腹腔注射L-NNA和MSG,于7、30和70d测心率、血压,观察脑卒中情况。结果:(1)高血压对照组心率30、70d较正常对照组增快(P<0 05);注射L-NNA组较正常对照组增快,但仅在30、70d高于高血压对照组(P<0 05);注射MSG组心率30、70d较高血压对照组和注射L-NNA组减慢,但未恢复至正常对照组水平(P<0 05)。(2)高血压对照组各时期的血压均较正常对照组明显增高(P<0 05);注射L-NNA组的血压在7d较高血压对照组升高不明显,但30、70d增高显著(P<0 05);注射MSG组的血压较高血压对照组和注射L-NNA组明显下降,但仍未恢复至正常水平。(3)高血压对照组在70d均出现程度不等的脑卒中症状,有20%由于脑卒中死亡。注射L-NNA组从30d开始即出现不同程度的脑卒中症状,有33%由于脑卒中死亡。注射MSG组在实验的全程中均未出现脑卒中症状。结论:NO生成减少不仅影响大鼠心率,还参与高血压发生、发展,并可能与高血压晚期发生脑卒中有关。

Aim: To observe the influence of N ω-nitro-L-arginine(L-NNA) and L-glutamic acid monoammonium salt(MSG) on heart rate, blood pressure and stroke in hypertensive rats. Methods: Measure the heart rate and blood pressure, then observe the stroke symptom after intraperitoneal injection of L-NNA and MSG. Results: (1) The heart rate in hypertension group increased significantly; After injecting L-NNA, the heart rate is higher than that of the hypertension group at 30 d, 70 d. Injecting MSG could slow the heart rate of the hypertension group at 30 d, 70 d. However, the heart rate couldn't reach to the normal level. (2)The blood pressure of the hypertension group is higher than that of the control group. After injecting L-NNA, the blood pressure increased significantly at 30 d, 70 d. Injecting MSG the blood pressure changed adversely, but the blood pressure is still abnormal. (3)All the rats at 70 d occur the stroke in hypertension group and 20% of them are died of the stroke. After injecting L-NNA, the stroke appears in advance at 30d and the mortality is 33%, more than 20% in the hypertension group. Meanwhile, injecting MSG can protect the rats from the stroke. Conclusion:The reduce of nitric oxide not only influences the heart rate of rats, but also takes part in the development of the hypertension, and the nitric oxide may be associated with the occurrence of the stroke in the late period of the hypertension.