Achar Eduardo, Achar Rosi A N, Paiva Therezinha B, Campos Alexandre H, Schor Nestor
Nephrology Division, Escola Paulista de Medicina/Universidade Federal de São Paulo, Brazil.
Kidney Int. 2003 Oct;64(4):1356-64. doi: 10.1046/j.1523-1755.2003.00222.x.
We investigated the effects of amitriptyline in the urinary tract smooth muscle and urolithiasis.
Cats presenting with obstructive acute renal failure (ARF) received amitriptyline, and renal function and survival rates were analyzed. Isometric contractions and membrane potentials of rat, pig, or human isolated urinary tract smooth muscle were recorded in the presence or absence of amitriptyline.
Twenty cats with obstructive ARF caused by urethral plugs received amitriptyline. In all cases, plugs were completely eliminated, and renal function returned to normal, with a 100% survival rate in the follow-up. Amitriptyline produced potent relaxations in rat urethral strips, accompanied by significant reductions in urethral ring membrane potential. This effect was prevented by pretreatment of urethral rings with 4-aminopyridine (4-AP), a voltage-dependent potassium channel blocker. Amitriptyline abolished in a reversible manner acetylcholine-, bradykinin-, and KCl-induced contractions in rat isolated bladder, and this effect was also prevented by 4-AP. Of interest, spontaneous and KCl-induced contractions of pig and human isolated ureter were also blocked by amitriptyline.
Our results indicate that amitriptyline is an effective and potent relaxant of urinary tract smooth muscle and this effect is mediated by opening of voltage dependent-potassium channels. We suggest that amitriptyline administration may help to promote elimination of urinary calculi.
我们研究了阿米替林对尿路平滑肌和尿路结石的影响。
对出现梗阻性急性肾衰竭（ARF）的猫给予阿米替林，并分析其肾功能和存活率。在有或没有阿米替林存在的情况下，记录大鼠、猪或人离体尿路平滑肌的等长收缩和膜电位。
20只由尿道堵塞导致梗阻性ARF的猫接受了阿米替林治疗。在所有病例中，堵塞物均被完全清除，肾功能恢复正常，随访期间存活率为100%。阿米替林可使大鼠尿道条强力松弛，同时尿道环膜电位显著降低。用电压依赖性钾通道阻滞剂4-氨基吡啶（4-AP）预处理尿道环可防止这种作用。阿米替林以可逆方式消除大鼠离体膀胱中乙酰胆碱、缓激肽和氯化钾诱导的收缩，4-AP也可防止这种作用。有趣的是，阿米替林还可阻断猪和人离体输尿管的自发性收缩和氯化钾诱导的收缩。
我们的结果表明，阿米替林是一种有效且强力的尿路平滑肌松弛剂，这种作用是通过开放电压依赖性钾通道介导的。我们建议使用阿米替林可能有助于促进尿路结石的排出。
