Sympathetic innervation of the splanchnic region mediates the beneficial hemodynamic effects of 8-OH-DPAT in hemorrhagic shock.
Sympathetic innervation of the splanchnic region mediates the beneficial hemodynamic effects of 8-OH-DPAT in hemorrhagic shock.
复制标题
内脏区域的交感神经支配介导 8-OH-DPAT 在失血性休克中的有益血流动力学作用。
DOI：
10.1152/ajpregu.00689.2011
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Scrogin,KarieE
中科院分区：
文献类型：
--
作者：
Tiniakov,Ruslan;Pahan,Kalipada;Scrogin,KarieE
给予5-HT 1A受体激动剂8-OH-DPAT可改善低血容量性休克清醒大鼠的心血管血流动力学和组织氧合。这种效应是由交感神经依赖性静脉张力增加介导的。为了确定内脏神经在该反应中的作用，在固定动脉血压失血性休克（即，维持50 mmHg动脉压25 min）。内脏去神经减少基线静脉张力测量的平均循环充盈压（MCFP）和加速失血过程中的低血压发作。内脏去神经不影响8-OH-DPAT的即时升压作用，但逆转了药物的持久升压作用，以及其增加MCFP和改善代谢性酸中毒的能力。与SD一样，肾上腺去髓质（ADMX）降低了基线MCFP，加速了对抽血的反应，但也减少了维持动脉血压在50 mmHg所需的抽血量。8-OH-DPAT在ADMX大鼠给药后早期升高MCFP，但在整个出血后期间，这种反应并不持续。在固定容量出血模型中，8-OH-DPAT继续升高ADMX大鼠的血压。然而，与假手术动物相比，它只产生了MCFP的短暂和可变的上升。数据表明，8-OH-DPAT通过激活内脏神经增加低血容量大鼠的静脉收缩并改善酸碱平衡。这种效应部分是由于肾上腺髓质的激活。
Administration of the 5-HT1Areceptor agonist, 8-OH-DPAT, improves cardiovascular hemodynamics and tissue oxygenation in conscious rats subjected to hypovolemic shock. This effect is mediated by sympathetic-dependent increases in venous tone. To determine the role of splanchnic nerves in this response, effects of 8-OH-DPAT (30 nmol/kg iv) were measured following fixed-arterial blood pressure hemorrhagic shock (i.e., maintenance of 50 mmHg arterial pressure for 25 min) in rats subjected to bilateral splanchnic nerve denervation (SD). Splanchnic denervation decreased baseline venous tone as measured by mean circulatory filling pressure (MCFP) and accelerated the onset of hypotension during blood loss. Splanchnic denervation did not affect the immediate pressor effect of 8-OH-DPAT but did reverse the drug's lasting pressor effect, as well as its ability to increase MCFP and improve metabolic acidosis. Like SD, adrenal demedullation (ADMX) lowered baseline MCFP and accelerated the hypotensive response to blood withdrawal but also reduced the volume of blood withdrawal required to maintain arterial blood pressure at 50 mmHg. 8-OH-DPAT raised MCFP early after administration in ADMX rats, but the response did not persist throughout the posthemorrhage period. In a fixed-volume hemorrhage model, 8-OH-DPAT continued to raise blood pressure in ADMX rats. However, it produced only a transient and variable rise in MCFP compared with sham-operated animals. The data indicate that 8-OH-DPAT increases venoconstriction and improves acid-base balance in hypovolemic rats through activation of splanchnic nerves. This effect is due, in part, to activation of the adrenal medulla.