von der Leyen H, Schmitz W, Scholz H, Scholz J, Lohse M J, Schwabe U
Abteilung Allgemeine Pharmakologie, Universitäts-Krankenhaus Eppendorf, Universität Hamburg, Federal Republic of Germany.
Naunyn Schmiedebergs Arch Pharmacol. 1989 Aug;340(2):204-9. doi: 10.1007/BF00168970.
The effects of the A1 adenosine receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) on force of contraction were examined in isolated electrically driven auricles and papillary muscles from guinea-pigs in the absence and presence of (-)-N6-phenylisopropyladenosine (PIA) and 5'-N-ethylcarboxamidadenosine (NECA). In auricles DPCPX (30-1000 mmol/l) alone increased force of contraction. DPCPX produced only a minor inhibition of phosphodiesterase I-III activity. PIA and NECA alone exerted concentration-dependent negative inotropic effects and the concentration-response curves for PIA and NECA were shifted competitively to the right by the adenosine receptor antagonist DPCPX with similar potency and efficacy. The pA2-value for the inhibition of the effects of PIA and NECA were 9.1 and 8.8, respectively. In papillary muscles DPCPX alone had no inotropic effect. In the presence of isoprenaline PIA and NECA alone exerted concentration-dependent negative inotropic effects and again DPCPX shifted the concentration-response curves for PIA and NECA competitively to the right with similar potency and efficacy. The pA2-value for the inhibition of the effects of PIA and NECA were 9.3 and 9.0, respectively. It is concluded that DPCPX is a potent competitive A1 adenosine receptor antagonist in guinea-pig atrial and ventricular cardiac preparations. Since PIA and NECA were equally potent the cardiac adenosine receptor may constitute a subtype of A1 adenosine receptors differing from the receptor in other tissues such as fat cells. Furthermore, DPCPX has a positive inotropic effect in atrial tissue which cannot be attributed to the A1 receptor antagonism.
在有无（-）-N6-苯异丙基腺苷（PIA）和5'-N-乙基羧酰胺腺苷（NECA）存在的情况下，研究了A1腺苷受体拮抗剂1,3-二丙基-8-环戊基黄嘌呤（DPCPX）对豚鼠离体电驱动心房和乳头肌收缩力的影响。在心房中，单独使用DPCPX（30 - 1000 mmol/l）可增加收缩力。DPCPX仅对磷酸二酯酶I - III活性有轻微抑制作用。单独使用PIA和NECA可产生浓度依赖性负性肌力作用，腺苷受体拮抗剂DPCPX以相似的效力和效能使PIA和NECA的浓度 - 反应曲线竞争性右移。抑制PIA和NECA作用的pA2值分别为9.1和8.8。在乳头肌中，单独使用DPCPX无肌力作用。在异丙肾上腺素存在的情况下，单独使用PIA和NECA可产生浓度依赖性负性肌力作用，DPCPX同样以相似的效力和效能使PIA和NECA的浓度 - 反应曲线竞争性右移。抑制PIA和NECA作用的pA2值分别为9.3和9.0。结论是，DPCPX是豚鼠心房和心室心脏制剂中一种有效的竞争性A1腺苷受体拮抗剂。由于PIA和NECA效力相同，心脏腺苷受体可能构成与其他组织如脂肪细胞中的受体不同类型的A1腺苷受体亚型。此外，DPCPX在心房组织中有正性肌力作用，这不能归因于A1受体拮抗作用。
