Immunohistochemical localization of angiotensin AT1 receptors in the rat carotid body
Immunohistochemical localization of angiotensin AT1 receptors in the rat carotid body
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DOI：
10.1016/j.acthis.2018.01.005
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发表时间：
2018-01-01
影响因子：
2.5
通讯作者：
Lazarov, Nikolai E.
中科院分区：
文献类型：
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作者：
Atanasova, Dimitrinka Y.;Dandov, Angel D.;Lazarov, Nikolai E.
颈动脉体 (CB) 是主要的外周动脉化学感受器，可启动呼吸和心血管调节以维持体内平衡。最近的证据表明，循环或局部产生的激素（如血管紧张素 II）通过 AT(1) 发挥作用。受体以旁分泌-自分泌方式调节其活性。本研究的目的是检查成年大鼠 CB 中 AT(1) 受体的免疫组织化学定位，并比较其在媒介物处理的动物中以及长期应用其选择性阻断剂氯沙坦后的表达。免疫组织化学显示，CB 肾小球的一个子集和邻近颈上神经节 (SCG) 中的绝大多数神经元具有强烈的 AT(1) 受体免疫反应性。在 CB 中，在通常聚集在细胞簇中的化学感应球细胞中观察到免疫染色，而其间的神经纤维和周围的大毛细血管呈免疫阴性。长时间外源性给予氯沙坦可显着降低 CB 血管球细胞和 SCG 神经元中 AT(1) 受体免疫染色的强度。我们的结果表明，在生理条件下，AT(1)受体在大鼠CB中大量表达，并且其表达通过氯沙坦治疗而下调。
The carotid body (CB) is a major peripheral arterial chemoreceptor that initiates respiratory and cardiovascular adjustments to maintain homeostasis. Recent evidence suggests that circulating or locally produced hormones like angiotensin II acting via AT(1). receptors modulate its activity in a paracrine-autocrine manner. The aim of this study was to examine the immunohistochemical localization of AT(1) receptor in the CB of adult rats and to compare its expression in vehicle-treated animals, and after the long-term application of its selective blocker losartan. Immunohistochemistry revealed that a subset of CB glomenruli and the vast majority of neurons in the adjacent superior cervical ganglion (SCG) were strongly AT(1) receptor-immunoreactive. In the CB immunostaining was observed in the chemosensory glomus cells typically aggregated in cell clusters while the nerve fibers in-between and large capillaries around them were immunonegative. Exogenous administration of losartan for a prolonged time significantly reduces the intensity of AT(1) receptor immunostaining in the CB glomus cells and SCG neurons. Our results show that AT(1) receptors are largely expressed in the rat CB under physiological conditions, and their expression is down-regulated by losartan treatment.