Lobanok L M, Kirienkov A E
Kosm Biol Aviakosm Med. 1988 Sep-Oct;22(5):64-8.
Experiments were performed on isolated hearts of adult (8-10 months old) and aged (24-26 months old) rats perfused with the Krebs-Henseleit solution according to the method of Langendorf. It was demonstrated that when oxygen supply was insufficient (pO2 of the perfusion solution-100 mm Hg), the chronotropic reaction of the heart to the stimulation of alpha- and beta-adrenergic receptors with phenylephrine hydrochloride (5 x 10(-7)--10(-5) M) and isoprenaline (10(-9)--10(-6) M), respectively, increased in adult rats and decreased in aged animals. Positive inotropic effects of adrenoagonists in hypoxic hearts diminished but their values as well as those at adequate oxygenation (pO2 = 600 mm Hg) were higher in aged rats. Stimulation of adrenoreceptors in the case of inadequate oxygenation increased hypoxic myocardial contracture, the increase being greater in adult rats.
按照Langendorf方法，对成年（8 - 10个月大）和老年（24 - 26个月大）大鼠的离体心脏进行实验，用Krebs - Henseleit溶液灌注。结果表明，当氧气供应不足时（灌注液的pO2为100 mmHg），成年大鼠心脏对分别用盐酸去氧肾上腺素（5×10(-7)--10(-5) M）和异丙肾上腺素（10(-9)--10(-6) M）刺激α和β肾上腺素能受体的变时反应增强，而老年动物的变时反应减弱。缺氧心脏中肾上腺素能激动剂的正性肌力作用减弱，但老年大鼠的这些作用值以及在充足氧合（pO2 = 600 mmHg）时的作用值更高。在氧合不足的情况下刺激肾上腺素能受体可增加缺氧心肌挛缩，成年大鼠的增加幅度更大。
