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目的 Salusin-α在大鼠尾端延髓腹外侧区(caudal ventrolateral medulla,CVLM)对心血管活动的调节作用及其机制研究尚不清楚。本实验主要探讨salusin-α在麻醉大鼠尾端延髓腹外侧区的心血管效应机制。方法雄性SD大鼠61只,其中25只大鼠单侧尾端延髓腹外侧区注射不同剂量salusin-α(0.04～4 pmol)或人工脑脊液(artificial cerebrospinalfluid,aCSF),观察salusin-α对大鼠血压和心率产生的影响。36只大鼠分别预先在尾端延髓腹外侧区给予人工脑脊液、非选择性谷氨酸受体拮抗剂犬尿希酸(kynurenic acid,Kyn)、毒蕈碱受体(M受体)阻断剂阿托品(atropine)、烟碱能受体(N受体)阻断剂六烃季铵(hexamethonium,Hex)或在头端延髓腹外侧区(rostral ventrolateral medulla,RVLM)用人工脑脊液/γ-氨基丁酸受体激动剂蝇蕈醇(5 pmol)预处理,观察对尾端延髓腹外侧区内salusin-α心血管效应受体机制。结果在尾端延髓腹外侧区单侧微量注射salusin-α产生剂量依赖性降低血压、减缓心率的作用。尾端延髓腹外侧区预先注射犬尿希酸(1 nmol)或六烃季铵均不影响尾端延髓腹外侧区微量注射salusin-α产生的降低血压、减缓心率的效应(P>0.05)。预先在尾端延髓腹外侧区微量注射阿托品或在头端延髓腹外侧区预先注射蝇蕈醇均能有效阻断salusin-α(4pmol)在尾端延髓腹外侧区产生的降低血压、减缓心率的效应(P<0.05)。结论 Salusin-α在大鼠尾端延髓腹外侧区产生的降低血压、减缓心率的作用可能由尾端延髓腹外侧区内M胆碱能受体介导,通过抑制头端延髓腹外侧区内前交感神经元活动产生的抑制效应。
Objective To investigate the regulatory effect of Salusin-α on cardiovascular activity and its mechanism in rat caudal ventrolateral medulla (CVLM). The main purpose of this study was to investigate the cardiovascular effects of salusin-α in the rostral ventrolateral medullae of anesthetized rats. Methods Sixty-one male Sprague-Dawley rats were randomly divided into 5 groups: control group, male Sprague-Dawley rats were injected with salusin-α (0.04 ~ 4 pmol) or artificial cerebrospinal fluid (CSFS) Blood pressure and heart rate effects. Thirty-six rats were given artificial cerebrospinal fluid, kynurenic acid (Kyn) and muscarinic receptor (M receptor), respectively, in the rostral ventrolateral medulla oblongata, and non-selective glutamate receptor antagonist Atropine, a nicotinic receptor (N-receptor) blocker hexamethonium (Hex), or an artificial cerebrospinal fluid / γ-amino group in the rostral ventrolateral medulla (RVLM) Butyric acid receptor agonist Muscimol (5 pmol) was used to pre-treat the cardiovascular effects of salusin-α in the rostral ventrolateral medulla oblongata. Results The unilateral microinjection of salusin-α into the rostral ventrolateral medulla caused a dose-dependent decrease of blood pressure and heart rate. Preinjection of kynurenine (1 nmol) or hexachloroquaternium into the rostral ventrolateral medullae did not affect the hypotensive effect and heart rate reduction (P> 0.05) of salusin-α produced by microinjection of salusin-α into the rostral ventrolateral medulla. Microinjection of atropine into the rostral ventrolateral medulla or pre-injection of muscimol into the rostral ventrolateral medullae could effectively block the hypotensive effect of salusin-α (4 pmol) on the rostral ventrolateral medulla. Effect (P <0.05). Conclusions The effect of Salusin-α on hypotension and heart rate reduction in rostral ventrolateral medulla may be mediated by M cholinergic receptors in rostral ventrolateral medulla. Inhibitory effect of sympathetic neuronal activity.