Stella L, Berrino L, Maione S, de Novellis V, Rossi F
Institute of Pharmacology and Toxicology, Faculty of Medicine and Surgery, II University of Naples, Italy.
Life Sci. 1993;53(10):755-63. doi: 10.1016/0024-3205(93)90497-q.
In order to define the purinergic receptors subtype involved in the control of cardiovascular activity, the effects of intracerebroventricular (icv 3rd ventricle) or intravenous (i.v.) injection of purinergic agonists and antagonists were evaluated on arterial blood pressure and heart rate of anaesthetized normotensive adult male rats. Adenosine (Ado) an A1 and A2 purinergic receptors agonist, N6-cyclohexyladenosine (CHA), an A1 receptor agonist and 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA), an A2 purinergic receptor agonist, were administered in rats by icv (0.01-0.05-0.1 microgram) and i.v. (0.1-0.5-1 microgram/kg) injections. The animals treated with adenosine were either pretreated with an A1 (8-cyclopenthyl-1,3-dimethylxanthine, CPT) an A2 (3,7dimethyl-1-propargylxanthine, DMPX) or an A1-A2 (aminophylline, APH) purinergic receptor antagonist by icv (0.05 microgram) or i.v. (0.5 microgram/kg) injected or not at all pretreated. Ado, CPCA and CHA produced a dose-dependent decrease in arterial blood pressure and heart rate. The effects of CHA were less marked than those caused by Ado and CPCA. The icv and i.v. pretreatment with aminophylline, CPT and DMPX inhibited arterial hypotension and bradycardia induced by Ado, CHA and CPCA. The inhibitor effects of aminophylline and DMPX were stronger than those caused by CPT. These results showed that in the cerebral areas near the 3rd ventricle the purinergic system plays an important role in the control of cardiovascular function. The involvement of A2 purinergic receptors after administration of adenosine or its analogs on central and peripheral cardiovascular activity was also confirmed.
为了确定参与心血管活动调控的嘌呤能受体亚型，研究了经脑室内（第三脑室）或静脉注射嘌呤能激动剂和拮抗剂对麻醉的正常血压成年雄性大鼠动脉血压和心率的影响。给大鼠脑室内注射（0.01 - 0.05 - 0.1微克）和静脉注射（0.1 - 0.5 - 1微克/千克）腺苷（Ado），一种A1和A2嘌呤能受体激动剂、N6 - 环己基腺苷（CHA），一种A1受体激动剂以及5'-（N - 环丙基）- 羧酰胺腺苷（CPCA），一种A2嘌呤能受体激动剂。用腺苷处理的动物，要么预先经脑室内（0.05微克）或静脉注射（0.5微克/千克）给予A1（8 - 环戊基 - 1,3 - 二甲基黄嘌呤，CPT）、A2（3,7 - 二甲基 - 1 - 丙炔基黄嘌呤，DMPX）或A1 - A2（氨茶碱，APH）嘌呤能受体拮抗剂，要么根本不进行预处理。Ado、CPCA和CHA使动脉血压和心率呈剂量依赖性下降。CHA的作用不如Ado和CPCA明显。氨茶碱、CPT和DMPX的脑室内和静脉预处理抑制了Ado、CHA和CPCA诱导的动脉低血压和心动过缓。氨茶碱和DMPX的抑制作用比CPT更强。这些结果表明，在第三脑室附近的脑区，嘌呤能系统在心血管功能调控中起重要作用。腺苷或其类似物给药后A2嘌呤能受体在中枢和外周心血管活动中的参与也得到了证实。
