BRAIN ANGIOTENSIN RECEPTOR FUNCTION, CONTROL, & ANATOMY

长期的目标是表征血管紧张素能活性在 CNS。 第一个具体的目的是检查脑血管紧张素（Ang II） 使用匀浆放射性配体结合技术的受体药理学。 这些研究将检查脑血管紧张素II受体是否存在于更多的 一个子类型。 血管紧张素Ⅱ受体位点与 测定不同脑区的125I-Sar-1、Ile 8-Ang II。 如果 观察到结合亲和力的显著差异，这将表明 大脑中存在多种血管紧张素II受体亚型 Ang的进一步研究 II受体亚型将使用Ang II类似物来区分亚型， 对不同类似物的不同亲和力。 这些研究将被延长 研究血管紧张素II受体位点药理学在离散核的 125I-Sar-1，Ile 8-Ang II体外定量放射自显影 与组织切片结合。 进一步的研究将调查是否存在 的可相互转换的高和低亲和力激动剂结合状态， 脑血管紧张素Ⅱ受体。 放射性标记的血管紧张素II拮抗剂的结合 将在不同浓度的血管紧张素II或 在存在和不存在三磷酸鸟苷的情况下， (GTP)或稳定的GTP类似物。 其他受体系统的类似研究 包括外周组织中的血管紧张素II受体， 受体的低亲和力状态。 第二个具体目标是检查的功能神经解剖学的 脑血管紧张素Ⅱ受体。 这些研究将主要涉及分析 使用体外受体在离散脑区域中结合血管紧张素II 放射自显影 将对大鼠进行各种处理，例如， 慢性和急性脑室内施用Ang II或其 拮抗剂，电解或化学损伤的特定脑区， 含有神经元或特定亚细胞的特定神经递质 神经元的元素。 根据放射性标记的血管紧张素II的变化， 结合到不同的大脑区域，这些研究应该会导致 脑中含有血管紧张素II的神经元成分的表征 受体，大脑中将投射发送到大脑区域的部位 含有血管紧张素II受体，神经递质亚型（例如， 去甲肾上腺素能，多巴胺能）的神经元含有和II受体， - Ang II在脑中的神经递质和/或神经激素作用，和 血管紧张素能活性是否调节脑中的血管紧张素II受体。

The long-term objective is to characterize angiotensinergic activity in the CNS. The first specific aim is to examine the brain angiotensin (Ang II) receptor pharmacology using homogenate radioligand binding techniques. These studies will examine whether brain Ang II receptors exist in more than one subtype. The binding affinity of Ang II receptor sites for 125I-Sar-1,Ile8-Ang II in different brain areas will be determined. If significant differences in binding affinity are observed, this will suggest that multiple brain Ang II receptor subtypes exist. Further studies of Ang II receptor subtypes will use Ang II analogs to discriminate subtypes with different affinities for different analogs. These studies will be extended to examine the Ang II receptor site pharmacology in discrete nuclei of the brain using quantitative in vitro autoradiography of 125I-Sar-1,Ile8-Ang II binding to tissue sections. Further studies will investigate the existence of interconvertible high and low affinity agonist binding states of the brain Ang II receptor. The binding of a radiolabeled antagonist of Ang II will be carried out in the presence of varying concentrations of Ang II or its agonist analogs in the presence and absence of guanosine triphosphate (GTP) or a stable analog of GTP. Similar studies of other receptor systems including Ang II receptors in peripheral tissues have demonstrated high and low affinity states of the receptors. The second specific aim is to examine the functional neuroanatomy of the brain Ang II receptor. These studies will primarily involve analysis of Ang II binding in discrete brain regions using in vitro receptor autoradiography. Rats will be subjected to various treatments, e.g., chronic and acute intraventricular administration of Ang II or its antagonist, electrolytic or chemical lesions of specific brain areas, specific neurotransmitter containing neurons or specific subcellular elements of neurons. Based upon the alterations in radiolabeled Ang II binding to various brain regions, these studies should lead to a characterization of the neuronal elements in the brain which contain Ang II receptors, the sites in the brain which send projections to brain areas containing Ang II receptors, the neurotransmitter subtype (e.g., noradrenergic, dopaminergic) of neurons containing And II receptors, the neurotransmitter and/or neurohormonal role of Ang II in the brain, and whether angiotensinergic activity regulates Ang II receptors in the brain.