Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceará, Laboratório Escola Prof Luiz Capelo, Caixa Postal 3157, 60.430-270 Fortaleza, Brazil.
Life Sci. 2010 Mar 13;86(11-12):441-7. doi: 10.1016/j.lfs.2010.01.016. Epub 2010 Feb 4.
We assessed the effects of right atrial stretch on gastric tone and neuro-humoral pathways involved in this phenomenon.
Anesthetized male rats were submitted for monitoring of the mean arterial pressure (MAP) and central venous pressure (CVP). A balloon catheter positioned into the stomach monitored by plethysmography the gastric volume (GV). All rats were monitored for 55-min. After the first 20-min of monitoring (basal period), rats were either submitted to a 5-min interval of atrial stretch (AS) or maintained as controls. An intra-atrial balloon catheter was distended with 30, 50, or 70 microL of saline. GV and hemodynamic data were also monitored for a further 30-min. Another set of rats, either previously submitted to subdiaphragmatic vagotomy or splanchnicectomy plus celiac ganglionectomy or maintained as controls (sham), were also submitted to AS. Each subset consisted of six rats. The plasma level of the atrial natriuretic peptide (ANP) was measured in another group of rats. Data were compared by ANOVA followed by Bonferroni's test.
In control rats, the GV, MAP, and CVP remained at stable levels throughout the studies. In addition to increase the CVP, AS also decreased (P<0.05) the GV by 14%, 11.5%, and 16.5% in the 30, 50, and 70 microL groups, respectively. Vagotomy prevented the GV decrease. In contrast, the AS decreased (P<0.05) the GV by 21.3% in splanchnicectomized rats.
AS decreased the GV of rats in a volume-dependent manner, a phenomenon prevented by vagotomy but enhanced by celiac ganglionectomy.
我们评估了右心房扩张对胃张力和参与这一现象的神经激素途径的影响。
麻醉雄性大鼠接受平均动脉压（MAP）和中心静脉压（CVP）监测。一个置于胃内的气囊导管通过体积描记法监测胃体积（GV）。所有大鼠均监测 55 分钟。在监测的前 20 分钟（基础期）后，大鼠要么接受 5 分钟的心房扩张（AS），要么作为对照。心房内的气球导管用 30、50 或 70μL 生理盐水扩张。GV 和血液动力学数据也监测了另外 30 分钟。另一组大鼠，要么之前接受过膈下迷走神经切断术，要么接受过内脏切除术加腹腔神经节切除术，要么作为对照（假手术），也接受了 AS。每个亚组由 6 只大鼠组成。另一组大鼠测量了心房利钠肽（ANP）的血浆水平。数据通过方差分析后进行 Bonferroni 检验进行比较。
在对照大鼠中，GV、MAP 和 CVP 在整个研究过程中保持稳定水平。除了增加 CVP 外，AS 还分别使 30、50 和 70μL 组的 GV 降低了 14%、11.5%和 16.5%。迷走神经切断术防止了 GV 的下降。相反，内脏切除术使 GV 在交感神经节切除大鼠中降低了 21.3%。
AS 以容量依赖性方式降低大鼠的 GV，这一现象被迷走神经切断术阻止，但被腹腔神经节切除术增强。
