Ambühl P, Gyurko R, Phillips M I
University of Florida, College of Medicine, Department of Physiology, Gainesville 32610, USA.
Regul Pept. 1995 Oct 20;59(2):171-82. doi: 10.1016/0167-0115(95)00092-p.
Intracerebroventricular (i.c.v.) injections of antisense oligonucleotides against mRNA of the angiotensin type 1 (AT1) receptor have been shown to reduce blood pressure in spontaneously hypertensive (SHR) rats and angiotensin II-induced drinking in both SHR and Sprague-Dawley (SD) rats. The present investigation was designed to quantify the effect of i.c.v. injections of antisense oligonucleotides to the AT1 receptor mRNA on brain angiotensin receptors using membrane binding and autoradiographic analysis. Control injections contained sense or scrambled oligonucleotides or saline. Three daily injections of antisense oligonucleotides into the third ventricle of SD rats decreased the AT1 receptor number significantly by 25% in a hypothalamic tissue block. AT2 receptors were not altered. Autoradiography showed a decrease in angiotensin receptor number in hypothalamic nuclei and in the anteroventral region of the third ventricle (AV3V) after antisense treatment. AT2 receptors were not reduced indicating the AT1 antisense oligonucleotides were specific. In a second series of experiments, single injections of antisense oligonucleotides into the lateral ventricle of SHR rats were tested. Antisense oligonucleotides produced a significant decrease in receptor number in the same hypothalamic area. Sense and scrambled oligonucleotides did not decrease the receptor numbers significantly. The decreases observed after injection of antisense oligonucleotides were between 15 and 30%. These changes may be sufficient to account for the physiological effects of i.c.v. injections of antisense oligonucleotides to AT1 receptor mRNA.
脑室内（i.c.v.）注射针对血管紧张素1型（AT1）受体mRNA的反义寡核苷酸已被证明可降低自发性高血压（SHR）大鼠的血压，并减少SHR和Sprague-Dawley（SD）大鼠中血管紧张素II诱导的饮水。本研究旨在通过膜结合和放射自显影分析来量化脑室内注射针对AT1受体mRNA的反义寡核苷酸对脑内血管紧张素受体的影响。对照注射包含正义或乱序寡核苷酸或生理盐水。每天向SD大鼠第三脑室注射三次反义寡核苷酸，可使下丘脑组织块中的AT1受体数量显著减少25%。AT2受体未发生改变。放射自显影显示，反义治疗后下丘脑核和第三脑室前腹侧区域（AV3V）的血管紧张素受体数量减少。AT2受体未减少，表明AT1反义寡核苷酸具有特异性。在第二系列实验中，测试了向SHR大鼠侧脑室单次注射反义寡核苷酸的情况。反义寡核苷酸使同一下丘脑区域的受体数量显著减少。正义和乱序寡核苷酸未显著降低受体数量。注射反义寡核苷酸后观察到的减少幅度在15%至30%之间。这些变化可能足以解释脑室内注射针对AT1受体mRNA的反义寡核苷酸的生理效应。
