Sakamoto M, Yasumoto M, Ohsumi H, Choi H, Shibata Y, Kano T
Department of Anaesthesiology, Kumamoto University School of Medicine, Japan.
Br J Anaesth. 1994 Sep;73(3):384-7. doi: 10.1093/bja/73.3.384.
We have studied the effects of midazolam and flumazenil on the carotid sinus baroreflex, by examining mean arterial pressure (MAP) and heart rate (HR) responses to partial or complete bilateral carotid occlusion (BCO) in 12 conscious rabbits after aortic denervation. In eight rabbits, the responses to complete BCO were evaluated before and after cumulative doses of midazolam 0.5 and 1.0 mg kg-1, and after flumazenil 0.3 mg kg-1 following administration of midazolam. Midazolam and flumazenil had no effect on MAP or HR before complete BCO and neither affected the MAP response to complete BCO. Midazolam 0.5 and 1.0 mg kg-1 decreased the HR response to 60% and 58% of control, respectively. Flumazenil restored the midazolam-induced depression of the HR response to the control level. In the other four rabbits, we examined the MAP and HR responses to partial BCO (carotid artery pressure reduced by 5, 10 and 20 mm Hg) before and after midazolam 0.5 mg kg-1 and after flumazenil 0.3 mg kg-1 following administration of midazolam. The response to partial occlusion showed the same tendency as the response to complete BCO. These results indicate that midazolam attenuated the HR response of the carotid sinus baroreflex, flumazenil restored this midazolam-induced depression and neither drug affected the MAP response.
我们通过检测12只去主动脉神经的清醒家兔在部分或完全双侧颈动脉闭塞（BCO）时的平均动脉压（MAP）和心率（HR）反应，研究了咪达唑仑和氟马西尼对颈动脉窦压力反射的影响。在8只家兔中，评估了累积剂量的咪达唑仑0.5和1.0 mg kg-1给药前后以及咪达唑仑给药后氟马西尼0.3 mg kg-1给药后对完全BCO的反应。在完全BCO之前，咪达唑仑和氟马西尼对MAP或HR均无影响，且两者均不影响对完全BCO的MAP反应。咪达唑仑0.5和1.0 mg kg-1分别使HR反应降低至对照的60%和58%。氟马西尼将咪达唑仑诱导的HR反应抑制恢复至对照水平。在另外4只家兔中，我们检测了咪达唑仑0.5 mg kg-1给药前后以及咪达唑仑给药后氟马西尼0.3 mg kg-1给药后对部分BCO（颈动脉压力降低5、10和20 mmHg）的MAP和HR反应。对部分闭塞的反应与对完全BCO的反应显示出相同的趋势。这些结果表明，咪达唑仑减弱了颈动脉窦压力反射的HR反应，氟马西尼恢复了这种咪达唑仑诱导的抑制，且两种药物均不影响MAP反应。
