Aldred G P, Chai S Y, Song K, Zhuo J, MacGregor D P, Mendelsohn F A
University of Melbourne, Department of Medicine, Austin Hospital, Heidelberg, Australia.
Regul Pept. 1993 Mar 19;44(2):119-30. doi: 10.1016/0167-0115(93)90235-z.
We have determined the distribution of angiotensin II receptor subtypes in rabbit brain using in vitro autoradiography. AT1 receptors were found in very high concentrations in the forebrain circumventricular organs--the subfornical organ, organum vasculosum of the lamina terminalis, and the median eminence as observed in other mammals. However, there was very little labeling in the area postrema. In the paraventricular nucleus, median preoptic nucleus, supraoptic nucleus there were high levels of predominantly AT1 receptors. High densities of AT1 receptors were also found in the nucleus of the solitary tract and the rostral and caudal ventrolateral medulla. All of these regions have putative roles in the regulation of blood pressure and fluid and electrolyte balance. In the rabbit brain there is less AT2 receptor binding than the rat, with most AT2 binding found in the molecular layer of the cerebellum and in the septohypothalamic nucleus. In the subthalamic nucleus, the mediodorsal and ventroposterior nuclei of the thalamus, locus coeruleus and inferior olivary nuclei, areas containing mostly AT2 receptors in the rat, no binding was detected in the rabbit except in the locus coeruleus which contains moderate levels of AT1 receptors. Taken in conjunction with our previous results in the rat and human brains, these results reveal that AT1 receptors predominate in rostral forebrain, hypothalamus and autonomic control centers of the medulla oblongata in all three species. However, the distribution and density of AT2 bearing sites in regions such as the septum, thalamus subthalamic nuclei, locus coeruleus, cerebellum and inferior olivary nuclei show marked species differences.
我们已利用体外放射自显影技术确定了兔脑中血管紧张素II受体亚型的分布情况。如在其他哺乳动物中所观察到的那样，在前脑室周器官——穹窿下器官、终板血管器以及正中隆起中发现了高浓度的AT1受体。然而，最后区的标记却非常少。在室旁核、视前正中核、视上核中主要是高水平的AT1受体。在孤束核以及延髓头端和尾端腹外侧也发现了高密度的AT1受体。所有这些区域在血压、液体和电解质平衡的调节中都具有假定作用。兔脑中的AT2受体结合比大鼠少，大部分AT2结合见于小脑分子层和隔下丘脑核。在大鼠中主要含AT2受体的丘脑底核、丘脑背内侧核和腹后核、蓝斑和下橄榄核，在兔中未检测到结合，但在含有中等水平AT1受体的蓝斑中除外。结合我们之前在大鼠和人脑中的研究结果，这些结果表明，在所有这三个物种中，AT1受体在前脑嘴侧、下丘脑和延髓自主控制中心占主导。然而，在隔区、丘脑底核、蓝斑、小脑和下橄榄核等区域中含AT2位点的分布和密度存在明显的物种差异。
