Persson C G, Andersson K E
Acta Pharmacol Toxicol (Copenh). 1977 Apr;40(4):529-36.
The effects of 3-methylxanthine (3-MX), a major metabolite of theophylline in man, were studied and compared with those of theophylline in isolated preparations of human and guinea-pig airways, isolated guinea-pig hearts, and in anaesthetized cats. 3-MX was pharmacologically active, producing effects similar to those of theophylline. The guinea-pig and human airways preparations were relaxed; the rate and force of contraction of guinea-pig hearts were increased. In anaesthetized cats, 3-MX decreased the respiratory overflow and arterial blood pressure, and increased the heart rate. Theophylline was always more potent (between 1 and 5 times) than 3-MX. It is suggested that 3-MX may contribute to the effects of theophylline during long-term treatment.
研究了氨茶碱在人体内的主要代谢产物3-甲基黄嘌呤（3-MX）的作用，并将其与氨茶碱在人及豚鼠气道离体标本、豚鼠离体心脏以及麻醉猫体内的作用进行了比较。3-MX具有药理活性，产生的作用与氨茶碱相似。豚鼠和人的气道标本舒张；豚鼠心脏的收缩速率和力量增加。在麻醉猫中，3-MX降低了呼吸溢出量和动脉血压，并增加了心率。氨茶碱的效力总是比3-MX强（1至5倍）。有人提出，在长期治疗期间，3-MX可能对氨茶碱的作用有贡献。
