兔杏仁中央核中心区微量注射吗啡,纳洛酮对膈神经放电的影响

实验在24只家兔身上观察了微量注射吗啡、纳洛酮于杏仁中央核(ACE)中心区对膈神经放电的影响,同时监测动脉血压,主要结果如下:(1)ACE中心区微量注射m吗啡,不同动物出现两种不同的呼吸效应,一为吸气时程延长,膈神经放电积分幅值升高;二为膈神经放电积分幅值下降,呼吸时程无明显变化。(2)ACE中心区微量注射纳洛酮,呼吸频率增加,积分幅值升高,吸气时程缩短。(3)预先注射纳洛酮,可阻断吗啡在ACE中心区的吸气延长效应,而对其它的呼吸指标不产生影响。提示:ACE神经元上可能存在有内源性吗啡受体,内源性吗啡通过其受体可对呼吸产生影响。

THE RESPONSES OF PHRENIC DISCHARGES TO MICROINJECTION OF MORPHINE AND NALOXONE INTO CENTRAL NUCLEUS AMYGDALA OF RABBITS

Experiments were done on 24 urethan anesthetized (20%,, 1g/kg), vagatomizedand spontaneously breathing rabbits (2--3 kg). The effects on phrenic activity by microinjection of morphine and naloxone into central nucleus amygdala (ACE) were observed. The main results were as follows: (1) Injection of morphine resulted in two respiratory effects, firstly a marked increase in inspiratory time (T_i) and amplitude ofphrenic activity (AMP) with little changes of respiratory frequency (RF), and secondly a singificant decrease in AMP with little changes in T_i (2) Injection of naloxone resulted in increases in RF. AMP and decreases in T_i with no marked changes in bloodpressure. (3) Prolongation of inspiratory time by morphine can be blocked by previousinjection of naloxone. The results suggested that endogenous morphine in ACE have different effects onrespiration mediated by different receptor.