氯沙坦的外周降压效应和对缰核神经元单位放电的影响

Effect of losartan on arterial blood pressure and unit dischargings of neurons in habenular of rats

目的 :探讨氯沙坦 (腹腔注射 )对大鼠血压、心率及神经元电活动的影响。方法 :用生理记录仪记录大鼠腹腔注射氯沙坦前、后动脉血压及心率的变化。用玻璃微电极记录大鼠腹腔注射氯沙坦前、后外侧缰核及内侧缰核神经元单位放电的情况。结果 :低剂量氯沙坦 ( 2 mg· kg-1)对大鼠血压、心率无明显影响 ,而中、高剂量氯沙坦 ( 5 ,1 0 mg· kg-1)可明显地降低大鼠动脉血压。低、中剂量氯沙坦对外侧缰核及内侧缰核神经元单位放电无明显影响 ,而高剂量氯沙坦使外侧缰核 66.6%( 1 2 /1 8)单位放电的自发频率明显增加 ,使内侧缰核 61 .9% ( 1 3/2 1 )单位放电的自发频率明显减少。结论 :高剂量氯沙坦可明显降低大鼠的动脉血压 。

Objective: To investigate the effect of losartan given by intraperitoneal injection on arterial pressure(AP), heart rate (HR) and the involvement in the activity of unit neurons in rats. Methods: Physiological recorder was used to record any changes of AP and HR in rats before and after losartan was intraperitoneally injected. Glass micropipette was used to record any changes of unit dischargings of neurons in lateral habenular (LHb) and medial habenular (MHb) before and after losation was intraperitoneally injected. Results: AP were not significantly changed in low dosage of losartan. Howevr,AP were apparently decreased in middle and high dosage of losartan. Unit dischargings of neurons were not significantly changed in LHb and MHb in low and middle dosage of losarlan. Unit dischargings of neurons were increased in LHb (66.66%,12/18) and were decreased in MHb (61.9%,13/21) in high dosage losartan. Conclusion: AP of tested rat was significantly decreased in high dosage of losartan. Depressor effect of losartan was involved in the excition of neurons in LHb and the inhibition in MHb. [