Medullary pathway of the Bezold-Jarisch reflex in the rat.
Medullary pathway of the Bezold-Jarisch reflex in the rat.
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大鼠 Bezold-Jarisch 反射的髓质通路。
DOI：
10.1152/ajpregu.1992.263.6.r1195
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Guyenet,PG
中科院分区：
文献类型：
--
作者：
Verberne,AJ;Guyenet,PG
研究了氟烷麻醉瘫痪大鼠颈静脉注射5-羟色胺（5-HT）和苯二胍（PBG）引起的Bezold-Jarisch反射的中枢通路。5-HT和PBG产生低血压和腰椎交感放电抑制，通常先于交感神经兴奋。双侧微量注射肌尿酸（KYN；谷氨酸拮抗剂，1.25 nmol/侧）阻断孤立束核的Bezold-Jarish反射。双侧向髓质尾侧腹外侧注射KYN （5 nmol/侧）也阻断了反射。双侧向侧侧腹侧髓质（RVL）注射双丘碱（BIC； 100 pmol/侧）可减少反射的抑制成分和交感神经抑制成分，增强兴奋成分。Bezold-Jarisch反射的阻断或衰减总是伴随着动脉压力反射的阻断或衰减。RVL压敏神经元（n = 61）被PBG和5-HT抑制（放电减少约60%）。离子电泳应用BIC （n = 11个细胞），而不是士的宁（甘氨酸拮抗剂），阻断了5-HT和PBG对RVL神经元的抑制。Bezold-Jarisch反射的交感抑制成分可能使用类似于动脉压力反射的中枢通路。
The central pathway mediating the Bezold-Jarisch reflex elicited by jugular vein injection of serotonin (5-HT) and phenyl biguanide (PBG) was studied in halothane-anesthetized, paralyzed rats. 5-HT and PBG produced hypotension and inhibition of lumbar sympathetic discharge often preceded by sympathoexcitation. The Bezold-Jarish reflex was blocked by bilateral kynurenic acid (KYN; glutamate antagonist, 1.25 nmol/side) microinjection into the solitary tract nucleus. Bilateral KYN injection into the caudal ventrolateral medulla (5 nmol/side) also blocked the reflex. Bilateral injection of bicuculline methiodide (BIC; 100 pmol/side) into the rostral ventrolateral medulla (RVL) reduced the depressor and sympathoinhibitory components of the reflex and enhanced an excitatory component. Blockade or attenuation of the Bezold-Jarisch reflex was always associated with a concomitant blockade or attenuation of the arterial baroreflex. RVL barosensitive neurons (n = 61) were inhibited (> 60% reduction in firing) by PBG and 5-HT. Iontophoretic application of BIC (n = 11 cells), but not strychnine (glycine antagonist), blocked inhibition of RVL neurons by 5-HT and PBG. The sympathoinhibitory component of the Bezold-Jarisch reflex may use a central pathway similar to that of the arterial baroreflex.