Diederen W, Kadatz R
Arzneimittelforschung. 1981;31(1a):141-6.
2-(2,4-Dimethoxyphenyl)-1H-imidazo[4,5-b]-pyridine (AR-L 57 BS), 2-(4-methoxy-2-[(2-methylsulfinyl)ethoxy]-phenyl-3H-imidazo[4,5-b]pyridine (AR-L 100 BS) and 2-[(2-methoxy-4-methylsulfinyl)phenyl]-1H-imidazo[4,5-b]pyridine (AR-L 115 BS) increased force of contraction in isolated rat atria at 3-1000 mumol/l by maximally 100%. In anaesthetized cats dp/dtmax was augmented by maximally 141-216% at 0.1-10 mg/kg i.v. Heart rate rose after AR-L 57 BS and AR-L 115 BS by 17-38% and decreased after AR-L 100 BS by 17%. AR-L 57 BS and AR-L 115 BS had weak effects on blood pressure, AR-L 100 BS elevated blood pressure by more than 50%. The effects were rapid in onset and lasted up to 20 min after AR-L 57 BS and AR-L 100 BS and more than 50 min after AR-L 115 BS. Only AR-L 115 BS was orally active. Intravenous toxicity was lowest with AR-L 115 BS and highest with AR-L 100 BS. Oral toxicity was equal for the three compounds. The positive inotropic effects of the benzimidazoles were stronger than that of ouabain and comparable to those of theophylline and isoprenaline.
2-(2,4-二甲氧基苯基)-1H-咪唑并[4,5-b]吡啶(AR-L 57 BS)、2-(4-甲氧基-2-[(2-甲基亚磺酰基)乙氧基]苯基-3H-咪唑并[4,5-b]吡啶(AR-L 100 BS)和2-[(2-甲氧基-4-甲基亚磺酰基)苯基]-1H-咪唑并[4,5-b]吡啶(AR-L 115 BS)在3至1000μmol/l浓度下可使离体大鼠心房收缩力最大增加100%。在麻醉猫中，静脉注射0.1至10 mg/kg时，dp/dtmax最大增加141%至216%。AR-L 57 BS和AR-L 115 BS使心率升高17%至38%，AR-L 100 BS使心率降低17%。AR-L 57 BS和AR-L 115 BS对血压影响较弱，AR-L 100 BS使血压升高超过50%。这些作用起效迅速，AR-L 57 BS和AR-L 100 BS作用持续长达20分钟，AR-L 115 BS作用持续超过50分钟。只有AR-L 115 BS具有口服活性。静脉毒性以AR-L 115 BS最低，以AR-L 100 BS最高。三种化合物的口服毒性相当。苯并咪唑类的正性肌力作用强于哇巴因，与茶碱和异丙肾上腺素相当。
