在8周龄的自发性高血压大鼠中，心脏压力反射已经迟钝。
Cardiac baroreflex is already blunted in eight weeks old spontaneously hypertensive rats.
作者信息
Cisternas José R, Valenti Vitor E, Alves Thales B, Ferreira Celso, Petenusso Márcio, Breda João R, Pires Adilson C, Tassi Nadir, de Abreu Luiz Carlos
机构信息
Department of Morphology and Physiology, School of Medicine of ABC, Av, Príncipe de Gales, 821, Santo André 09060-650, Brazil.
出版信息
Int Arch Med. 2010 Jan 27;3:2. doi: 10.1186/1755-7682-3-2.
BACKGROUND
The literature did not evidence yet with which age spontaneously hypertensive rats (SHR) start to present baroreflex reduction. We endeavored to evaluate the baroreflex function in eight-week-old SHR.
METHODS
Male Wistar Kyoto (WKY) normotensive rats and SHR aged eight weeks were studied. Baroreflex was calculated as the variation of heart rate (HR) divided by the mean arterial pressure (MAP) variation (DeltaHR/DeltaMAP) tested with a depressor dose of sodium nitroprusside (SNP, 50 microg/kg) and with a pressor dose of phenylephrine (PHE, 8 microg/kg) in the right femoral venous approach through an inserted cannula in the animals. Significant differences for p < 0.05.
RESULTS
Baseline MAP (p < 0.0001) and HR (p = 0.0028) was higher in SHR. Bradycardic peak was attenuated in SHR (p < 0.0001), baroreflex gain tested with PHE was also reduced in the SHR group (p = 0.0012). PHE-induced increase in MAP was increased in WKY compared to SHR (p = 0.039). Bradycardic reflex responses to intravenous PHE was decreased in SHR (p < 0.0001).
CONCLUSION
Eight weeks old SHR already presents impairment of the parasympathetic component of baroreflex.
背景
文献中尚未证实自发性高血压大鼠（SHR）从哪个年龄开始出现压力反射减弱。我们致力于评估8周龄SHR的压力反射功能。
方法
对8周龄的雄性Wistar Kyoto（WKY）正常血压大鼠和SHR进行研究。通过在动物右股静脉插入插管，经静脉给予降压剂量的硝普钠（SNP，50微克/千克）和升压剂量的去氧肾上腺素（PHE，8微克/千克）来测试压力反射，计算方法为心率（HR）变化除以平均动脉压（MAP）变化（ΔHR/ΔMAP）。p < 0.05时有显著差异。
结果
SHR的基线MAP（p < 0.0001）和HR（p = 0.0028）较高。SHR的心动过缓峰值减弱（p < 0.0001），SHR组用PHE测试的压力反射增益也降低（p = 0.0012）。与SHR相比，WKY中PHE诱导的MAP升高幅度增加（p = 0.039）。SHR对静脉注射PHE的心动过缓反射反应降低（p < 0.0001）。
结论
8周龄的SHR已经出现压力反射副交感神经成分的损害。
Zotero 插件