Effect of reversible inactivation of central nucleus of the Amygdala on the blood pressure of the hypertensive rats

The brain rennin-angiotensin system (RAS) has an important role in the regulation of cardiovascular function. The aim of the present study was to determine the effects of reversible inactivation of the ACe on normotensive and hypertensive rats (renal hypertension). Two groups of normotensive Wistar rats were selected for this study. In one group, hypertension was induced by Goldblatt method and another group was subjected to sham procedure. After 6 weeks, tests were performed on anesthetized rats with Urethane (1.5mg/kg). In order to perform bilateral reversible inactivation, lidocaine (1μl) was injected through guide cannuli that had been implanted in the ACe. Then direct measurements of femoral blood pressure were recorded just before and 5, 10, 20, 40, and 60 minutes after injection of lidocaine. Considering the baseline values, degree of changes was determined and compared between the two groups. Our results revealed that sham-inactivation led to a significant increase of blood pressure only at 5 minutes after injection (P<0.05). There was no significant difference in blood pressure at different times before and after injection of lidocaine in the hypertensive group. This study concludes that the change in the Ace activity during induction of hypertension is due to the change in RAS activity.