Departament of Physiological Sciences, Universidade Federal de Goiás, Goiânia, GO, Brazil.
Auton Neurosci. 2011 Feb 24;160(1-2):37-41. doi: 10.1016/j.autneu.2010.11.009. Epub 2010 Dec 10.
The peripheral hyperosmolarity elicited by intravenous infusion of hypertonic saline brings potential benefits to the treatment of hemorrhage. The neural mechanisms involved in these beneficial effects remain unknown. The present study examines the role of carotid chemoreceptors in cardiovascular responses induced by hypertonic saline after hypovolemic hemorrhage in rats. Male Wistar rats (300-400 g) were anesthetized with thiopental, and instrumented for recording of mean arterial pressure. Arterial pressure was reduced to 60 mm Hg by withdrawal of arterial blood over 10 min, and maintained at this level for 60 min by withdrawal or infusion of blood. In control rats (n = 8) with intact chemoreceptors, the subsequent intravenous infusion of hypertonic saline (3M NaCl, 1.8 ml kg(-1) body weight, in 2 min) restored blood pressure (pressure increased from 61 ± 4 to 118 ± 5 mm Hg). In experimental rats (n = 8), the carotid body arteries were tied, 30 min after the beginning of the hypotensive phase, leaving the carotid chemoreceptors ischemic. In these rats, hypertonic saline failed to restore blood pressure (pressure increased from 55 ± 1 to 70 ± 6 mm Hg). These findings suggest that the restoration of blood pressure after hypovolemic hemorrhage induced by hypertonic saline depends on intact carotid chemoreceptors.
静脉输注高渗盐水引起的外周高渗性对出血治疗有潜在益处。涉及这些有益效果的神经机制尚不清楚。本研究在失血性休克大鼠中研究了颈动脉化学感受器在高渗盐水引起的心血管反应中的作用。雄性 Wistar 大鼠（300-400 g）用硫喷妥钠麻醉，并进行平均动脉压记录。通过在 10 分钟内抽取动脉血将动脉压降低至 60mmHg，并通过抽取或输注血液将其维持在 60 分钟。在完整化学感受器的对照大鼠（n=8）中，随后静脉输注高渗盐水（3M NaCl，1.8mlkg(-1)体重，在 2 分钟内）可恢复血压（血压从 61±4mmHg 升高至 118±5mmHg）。在实验大鼠（n=8）中，在低血压期开始 30 分钟后结扎颈动脉体动脉，使颈动脉化学感受器缺血。在这些大鼠中，高渗盐水未能恢复血压（血压从 55±1mmHg 升高至 70±6mmHg）。这些发现表明，高渗盐水引起的失血性休克后血压的恢复取决于完整的颈动脉化学感受器。
