氯沙坦和氨氯地平对高血压病患者血压、血尿酸的作用比较

[目的]比较氯沙坦和氨氯地平的降压疗效和对血尿酸的影响。[方法]选择大连医科大学第二临床学院北院心内科住院的高血压病人98例，随机分为两组：A组49例，晨服单一药氯沙坦50mg／d；B组49例，晨服单一药氨氯地平5mg／d，观察8周。治疗前后测血压、血尿酸。[结果]与用药前比较，服药8周后，两组血压均显著下降（P〈0．01），组间无差异（P〉0．05）；两组血尿酸均下降，与用药前比较，氯沙坦组下降显著（P〈0．05），氨氯地平组下降无显著性（P〉0．05）。[结论]氯沙坦与氨氯地平降压疗效相似，均可作为抗高血压一线用药。其中，氯沙坦对高尿酸血症的患者尤为首选。     

Mapping of angiotensin II receptor subtype heterogeneity in rat brain.

Angiotensin II (Ang II) exerts a number of central actions on fluid and electrolyte homeostasis, autonomic activity, and neuroendocrine regulation. In order to evaluate likely sites where these actions are mediated, Ang II receptor binding was localized in rat brain by in vitro autoradiography with the aid of the antagonist analogue 125I-[Sar1, Ile8]Ang II. Two subtypes of Ang II receptor have been identified using recently developed peptide and nonpeptide antagonists. In the periphery, the receptor subtypes differ in distribution, second messenger coupling, and function. Brain Ang II receptor subtypes were therefore differentiated into AT-1 (type I) and AT-2 (type II) subtypes by using unlabelled nonpeptide antagonists specific for the two Ang II subtypes. AT-1 binding was determined to be that inhibited by Dup 753 (10 microM) and AT-2 binding to be that inhibited by PD 123177 (10 microM). The reducing agent dithiothreitol (DTT) decreased binding to AT-1 receptors and enhanced binding to AT-2 receptors. Many brain structures, such as the vascular organ of the lamina terminalis, subfornical organ, median preoptic nucleus, area postrema, nucleus of the solitary tract, and dorsal motor nucleus of the vagus, which are known to be related to the central actions of Ang II, contain exclusively AT-1 Ang II receptors. By contrast, the locus coeruleus, ventral and dorsal parts of lateral septum, superior colliculus and subthalamic nucleus, many nuclei of the thalamus, and nuclei of the inferior olive contain predominantly AT-2 Ang II receptors. The detailed binding characteristics of each subtype were determined by competition studies with a series of analogues of angiotensin and antagonists. The pharmacological specificity obtained in rat superior colliculus and the nucleus of the solitary tract agreed well with published data on AT-1 and AT-2 receptors, respectively. There was a high degree of correlation between the distribution of Ang II binding sites with published data on Ang II-immunoreactive fields and on the sites of Ang II-responsive neurons. The present study also reveals pharmacological heterogeneity of brain Ang II receptors. The subtype-specific receptor mapping described here is relevant to understanding the role of angiotensin peptides in the central nervous system and newly discovered central actions of nonpeptide Ang II receptor antagonists.