Pressor and endocrine responses to lesions of canine rostral ventrolateral medulla.
Pressor and endocrine responses to lesions of canine rostral ventrolateral medulla.
复制标题
对犬头侧延髓腹外侧病变的升压和内分泌反应。
DOI：
10.1152/ajpheart.1994.266.6.h2520
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Dormer,KJ
中科院分区：
文献类型：
--
作者：
Stith,RD;Dormer,KJ
为了解红藻氨酸细胞毒性损伤延髓头端腹外侧区（RVLM）后动脉压（AP）降低的机制，记录了清醒放松狗的AP、心输出量（CO）、心率（HR）、血浆儿茶酚胺和皮质醇。在犬（n = 12）的降主动脉和主动脉弓上分别安装一个固态压力传感器和一个脉冲渡越时间超声流量计，开胸后定期或在安静状态下测定AP、CO、HR和血浆肾上腺素、去甲肾上腺素和皮质醇水平，持续2-3 wk，RVLM头侧C1区的细胞毒性损伤。在狗从损伤手术中恢复后，重复测量，与损伤前对照值相比，它们显示AP显著降低（-23.1 mmHg）和总外周阻力（-0.014外周阻力单位），但CO或HR无显著变化。AP的降低可能部分由血浆肾上腺素的显著降低（-47%）引起，去甲肾上腺素（-34%）和皮质醇（-66%）水平。病变部位对应于喙C1区，免疫细胞化学阳性苯乙醇胺-N-甲基转移酶（PNMT）。这些观察结果支持的概念，一个离散的网站在RVLM，划分由一个吻侧亚组的PNMT免疫反应细胞体，有助于直接交感神经兴奋性支持静息AP。然而，负责血管紧张素的神经递质仍然未知。这项研究还提供了新的信息，表明从这个假定的血管紧张素中心的儿茶酚胺和皮质醇调节的作用。
To understand the mechanism(s) of reduction in arterial pressure (AP) after kainic acid cytotoxic lesions in the rostral ventrolateral medulla (RVLM), recordings of AP, cardiac output (CO), heart rate (HR), plasma catecholamines, and cortisol were obtained from awake relaxed dogs. Mongrels (n = 12) were instrumented with a solid-state pressure transducer in the descending aorta and a pulse transit-time ultrasonic flowmeter on the aortic arch. After the dogs recovered from thoracotomy, AP, CO, HR, and plasma levels of epinephrine, norepinephrine, and cortisol were recorded periodically or measured at rest over 2–3 wk followed by unilateral, cytotoxic lesion placement in the rostral C1 area of the RVLM. After the dogs recovered from lesion surgery, the measurements were repeated, and, compared with prelesion control values, they showed significantly decreased AP (-23.1 mmHg) and total peripheral resistance (-0.014 peripheral resistance units) but no significant changes in CO or HR. The reduction in AP may be caused partially by significant reductions in plasma epinephrine (-47%), norepinephrine (-34%), and cortisol (-66%) levels. Lesion sites corresponded to the rostral C1 area, immunocytochemically positive for phenylethanolamine-N-methyltransferase (PNMT). These observations support the concept that a discrete site in the RVLM, demarcated by a rostral subgroup of PNMT-immunoreactive cell bodies, contributes to direct sympathoexcitatory support of resting AP. The neurotransmitter responsible for vasomotor tone, however, remains unknown. This study also provides new information suggesting a role for catecholamine and cortisol regulation from this putative vasomotor center.