Luheshi G, Zar A
Department of Pharmacological Sciences, Medical School, Newcastle Upon Tyne, U.K.
Eur J Pharmacol. 1990 Aug 28;185(2-3):203-8. doi: 10.1016/0014-2999(90)90641-i.
In order to determine the effectiveness of purinoceptor desensitization in blocking the non-cholinergic motor transmission in rat detrusor, isolated preparations of urinary bladder, pretreated with atropine 3 microM + indomethacin 10 microM were contracted by alpha, beta-methylene-ATP, a stable analogue of ATP and by electrical stimulation at frequencies of 1, 2, 4, 8 and 16 Hz. The mean maximum tension generated by alpha, beta-methylene-ATP was 43% of that by electrical field stimulation. Desensitization to the contractile action of alpha, beta-methylene-ATP was achieved by administration of alpha, beta-methylene-ATP 10 microM, three times at 10 min intervals. Responses to electrical field stimulation were reduced following induction of alpha, beta-methylene-ATP desensitization but a sizeable proportion of the response persisted (51% at 1 Hz; 29% at 8 Hz). Tetrodotoxin 0.5 microM abolished the responses to electrical field stimulation, persisting after alpha, beta-methylene-ATP desensitization. It is concluded that ATP is unlikely to be the sole non-cholinergic motor transmitter in the rat detrusor.
为了确定嘌呤受体脱敏在阻断大鼠逼尿肌非胆碱能运动传递中的有效性，用3 microM阿托品 + 10 microM吲哚美辛预处理的离体膀胱制备物，被ATP的稳定类似物α,β-亚甲基-ATP以及1、2、4、8和16 Hz频率的电刺激收缩。α,β-亚甲基-ATP产生的平均最大张力是电场刺激产生的最大张力的43%。通过间隔10分钟三次给予10 microMα,β-亚甲基-ATP实现对α,β-亚甲基-ATP收缩作用的脱敏。在诱导α,β-亚甲基-ATP脱敏后，对电场刺激的反应降低，但仍有相当比例的反应持续存在（1 Hz时为51%；8 Hz时为29%）。0.5 microM河豚毒素消除了对电场刺激的反应，在α,β-亚甲基-ATP脱敏后仍持续存在。结论是，ATP不太可能是大鼠逼尿肌中唯一的非胆碱能运动递质。
