Bottiglieri D F, Morse C A, Baker S P, Crews F T, Sumners C, Raizada M K
Department of Physiology, University of Florida, College of Medicine, Gainesville 32610.
Brain Res. 1988 Jan 26;439(1-2):187-94. doi: 10.1016/0006-8993(88)91475-8.
The specificity and molecular weights of alpha 1-adrenergic receptors in various tissues of spontaneously hypertensive (SH) rat were compared with normotensive controls (Wistar-Kyoto; WKY) with the use of [125I]HEAT and [125I]azidoprazosin, specific alpha 1-adrenergic receptor antagonists. Binding of [125I]HEAT to membranes prepared from SH rat brain hypothalamus was significantly higher, due to a 75% increase in the Bmax, than the WKY control. In contrast, the Bmax and Kd of [125I]HEAT binding to brainstem and liver membranes from SH rats were not significantly different from those of WKY controls. Competition-inhibition data suggested similar pharmacological specificity with potencies in the order of prazosin greater than yohimbine greater than propranolol for both WKY and SH rat membranes prepared from liver, hypothalamus, brainstem and neuronal cultures. Photoaffinity labeling of alpha 1-adrenergic receptors from hypothalamus, brainstem and neuronal cultures using [125I]azidoprazosin followed by SDS-PAGE and autoradiography showed the presence of one major band with a molecular weight (MW) of 105,000 Da for both WKY and SH rats. In contrast, labeling of liver alpha 1-adrenergic receptors revealed one major band with a MW of 60,000 Da. Quantitation of the 105,000-Da band from SH rat hypothalamic membranes demonstrated a 52% higher intensity compared with WKY controls. Neuronal cultures prepared from 1-day-old SH rats showed a similarly greater intensity of the 105,000-Da band compared with WKY controls.(ABSTRACT TRUNCATED AT 250 WORDS)
使用特异性α1 - 肾上腺素能受体拮抗剂[125I]HEAT和[125I]叠氮哌唑嗪，比较自发性高血压（SH）大鼠各种组织中α1 - 肾上腺素能受体的特异性和分子量与正常血压对照（Wistar - Kyoto；WKY）大鼠。[125I]HEAT与SH大鼠脑下丘脑制备的膜的结合显著更高，这是由于Bmax增加了75%，高于WKY对照。相反，[125I]HEAT与SH大鼠脑干和肝膜的结合的Bmax和Kd与WKY对照无显著差异。竞争抑制数据表明，对于从肝、下丘脑、脑干和神经元培养体制备的WKY和SH大鼠膜，其药理特异性相似，效力顺序为哌唑嗪大于育亨宾大于普萘洛尔。使用[125I]叠氮哌唑嗪对下丘脑、脑干和神经元培养物中的α1 - 肾上腺素能受体进行光亲和标记，然后进行SDS - PAGE和放射自显影，结果显示WKY和SH大鼠均存在一条主要条带，分子量（MW）为105,000 Da。相反，肝α1 - 肾上腺素能受体的标记显示一条主要条带，MW为60,000 Da。对SH大鼠下丘脑膜中105,000 - Da条带的定量显示，与WKY对照相比，强度高52%。从1日龄SH大鼠制备的神经元培养物显示，与WKY对照相比，105,000 - Da条带的强度同样更高。（摘要截短于250字）
