β内啡肽对慢性缺氧大鼠呼吸的影响  

Respiratory effects of beta endorphin in chronic hypoxic rats

作　　者：许欣[1] 李强[1] 孙学军[2] 张世明[1] 张殿尧[1] 王成海[2] 

机构地区：[1]第二军医大学附属长海医院呼吸内科 [2]第二军医大学附属长海医院,上海200433

出　　处：《中华结核和呼吸杂志》1999年第12期734-738,共5页Chinese Journal of Tuberculosis and Respiratory Diseases

基　　金：国家自然科学基金!资助( 基金编号:39300060)

摘　　要：目的　探讨β内啡肽（βＥＰ） 在慢性缺氧大鼠呼吸调控中的作用。方法　采用放射免疫法测定慢性缺氧大鼠模型血浆及延髓、桥脑、下丘脑、中央灰质等神经核团中βＥＰ的含量变化，以及不同给药途径给予外源性βＥＰ对慢性缺氧大鼠呼吸功能的影响。正常大鼠侧脑室注射βＥＰ后，观察记录呼吸频率（ＲＲ） ；１０２ 只慢性缺氧大鼠随机分为：（１） 静脉组３６ 只，分别给予阿片受体拮抗剂纳洛酮（ＮＬＸ） 和不同剂量βＥＰ，记录ＲＲ 和潮气量（ＶＴ）；（２） 侧脑室组４８ 只，微量注射ＮＬＸ、βＥＰ，测定ＲＲ、ＶＴ及血气指标；（３） 孤束核组１８ 只，分别注射βＥＰ和人工脑脊液（ＡＣＳＦ） ，测定ＲＲ和ＶＴ。结果慢性缺氧模型延髓、桥脑、下丘脑、中央灰质和血浆βＥＰ的含量较对照组均显著升高（Ｐ＜０－０１）。给正常大鼠侧脑室注射βＥＰ后，ＲＲ 显著下降（ Ｐ＜ ０－０５） 。慢性缺氧大鼠静脉给予不同剂量βＥＰ和ＮＬＸ后，ＲＲ和ＶＴ 变化差异无显著性（Ｐ＞０－０５）。侧脑室注射ＮＬＸ后，ＲＲ显著增高（ Ｐ＜０－０５）。侧脑室及孤束核注射βＥＰ后显著降低ＲＲ、ＶＴ。侧脑室注射ＮＬＸ３０ 分钟时ＭＶ／ＰａＣＯ２ 较对照组显著升高（ｔ＝２－７６ ，Objective To assess the role of β EP in the physiological and pathophysiological process of respiratory regulation in chronic hypoxic rats. Methods The chronic hypoxic rat model was established by intravenous injections of papain 6 times, once a week. The concentration of β endorphin in medulla, pons, hypothalamus, central gray and plasma of chronic hypoxic rats were measured by radioimmunoassay. All animals were pretreated with sodium pentobartital (35 mg/kg) before experiment. 102 rats were randomly divided into three groups. Group 1 ( n =36). The respiratory rate (RR) and tidal volume (V T) were measured after intravenous injection of naloxone (NLX, 2 mg/kg), β EP (40 μg/kg, 160 μg/kg) or normal saline, Group 2 ( n =48) By the intracerebroventricular administration of NLX and β EP to the models, RR, V T and PaCO 2 were observed after microinjection 5, 15, 30, 45, 60 min. Group 3 ( n =18). The respiratory effects of β EP after directly into the nucleus tractus solitari of the anaesthetised rats were investigated. Results The β EP contents in medulla, pons, hypothalamus, central gray and plasma of chronic hypoxic rats were significantly increased compared with control subjects ( P <0.01). It suggested that the pathophysiology of chronic hypoxic process infleuced the contents of β EP in the CNS and plasma in rats. Intracerebroventricular microinjection of β EP in normal rats, resulted in a significant decrease in RR ( P <0.05). No significant difference in RR and V T was observved after intravenous injection of naloxone (2 mg/kg) and β EP (40 μg/kg, 160 μg/kg) in treatment group compared with the control group ( P >0.05), Intracerebroventricular microinjection of NLX in chronic hypoxic rats, resulted in a marked increase in RR ( P <0.05) and central hypercapnic sensitivity ( t =2.76, P <0.05), Intracerebroventriculalr microinjection of β EP in chronic hypoxic models, resulted in severe respiratory depression after injection 15, 30, 45, 60 min (RR t =3.41, 6.54

关 键 词：Β内啡肽 缺氧症 呼吸 

分 类 号：R364.4[医药卫生—病理学] R332.3[医药卫生—基础医学]