Fos immunoreactivity in the diagonal band and the perinuclear zone of the supraoptic nucleus after hypertension and hypervolaemia in unanaesthetized rats
Fos immunoreactivity in the diagonal band and the perinuclear zone of the supraoptic nucleus after hypertension and hypervolaemia in unanaesthetized rats
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DOI：
10.1046/j.0007-1331.2001.00765.x
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发表时间：
2002-03-01
影响因子：
3.2
通讯作者：
Sullivan, MJ
中科院分区：
文献类型：
--
作者：
Cunningham, JT;Grindstaff, RJ;Sullivan, MJ
我们用Fos免疫细胞化学方法研究了高血压和高血容量对Broca斜角带神经元和视上核核周区神经元的影响，这两个核团都参与了视上核加压素神经元的压力感受性调节。此外，我们使用去窦主动脉神经来检查动脉压力感受器在对这些血流动力学变化的反应中的作用。假手术组和去主动脉大鼠静脉滴注足以使血压升高的去甲肾上腺素2 h，对照组大鼠注入等量等渗盐水。仅假手术组大鼠血压升高时出现反射性心动过缓。大鼠静脉注入相当于体重10%的等渗盐水10min后，中心静脉压显著升高。在Broca斜角带和核周区，注射苯肾上腺素后，Fos阳性神经元的数量显著增加。去窦主动脉神经阻断了这两个区域的显著升高。体积扩张后，仅在视上核的核周区观察到Fos染色显著增加。这种增加不能被去窦主动脉神经所阻断。我们的结果表明，Broca的两条斜带。视上核的核周区通过刺激动脉压力感受器而被激活，而视上核的核周区在体积扩张时被刺激。此外，视上核体积扩张后核周区的激活不依赖于完整的动脉压力感受器。
We used Fos immunocytochemistry to study the effects of hypertension and hypervolaemia on neurones in the diagonal band of Broca and the perinuclear zone of the supraoptic nucleus, two nuclei that are both involved in the baroreceptor regulation of vasopressin neurones in the supraoptic nucleus. In addition, we used sino-aortic denervation to examine the role of arterial baroreceptors in the response to these haemodynamic changes. Sham-operated and sino-aortic denervated rats were infused with phenylephrine sufficient to increase blood pressure for 2 h. Control rats were infused with the same volume of isontonic saline. Only Sham sino-aortic denervated rats showed reflex bradycardia in response to the increased blood pressure. Volume expansion was produced by infusing the rats with isotonic saline equal to 10% of their body weight for 10 min, which significantly increased central venous pressure. In the diagonal band of Broca and the perinuclear zone, the number of Fos-positive neurones was significantly increased after phenylephrine infusion. Sino-aortic denervation blocked the significant increase in both regions. After volume expansion, a significant increase in Fos staining was observed only in the perinuclear zone of the supraoptic nucleus. This increase was not blocked by sino-aortic denervation. Our results indicate that both the diagonal band of Broca. and the perinuclear zone of the supraoptic nucleus are activated by stimulating arterial baroreceptors; however, the perinuclear zone of the supraoptic nucleus is stimulated during volume expansion. Furthermore, the activation of perinuclear zone of the supraoptic nucleus after volume expansion is not dependent on intact arterial baroreceptors.