7-溴化乙氧苯四氢巴马汀对α_1及多巴胺受体的作用

Effects of 7-bromethyoxybenzene-tetrahydropalmatine on α_1, Dopamine Receptors

7-溴化乙氧苯四氢巴马汀(7-bromethyoxybenzene-tetrahydropalmatine, EBP)能使甲氧胺引起的家兔主动脉条和大鼠肛尾肌收缩的量-效曲线平行右移,最大反应不降低,其PA′_2值分别为6.5和6.8。在豚鼠乳头状肌动作电位实验中,EBP均能表现出具有拮抗α_1受体之作用。在犬肾动脉等标本上,EBP能使多巴胺的量-效曲线非平行右移,PD′_2值为4.9。

The effects of 7-bromethyoxybenzene-tetrahydropalmatine(EBP) have been studied especially on α_1-adrenoceptor and dopamine (DA) receptor. EBP was found to produce parallel shifts to the right of the accumulative dose-response curves for methoxamine in rabbit aortic strips and rat anococcygeus muscles. Their PA_2 values were 6.5 and 6.8 respectively. The blocking effect of EBP on α_1-receptor was discovered also using conventional electrophsiological methods in guinea pig papillary muscles. The influence of dopamine on the dog renal aorta could be antagonized by EBP non-competitvely, PD'_2 value was 4.9, so does on the dog aorta abdominalis. The above-mentioned results indicate that EBP might be beneficial to the ischemic arrhythmias as a result of its α-adrenoceptor and dopamine receptor blocking actions.