THE EFFECTS OF BAY K-8644 AND NIFEDIPINE ON THE RESPONSES OF RAT URINARY-BLADDER TO ELECTRICAL-FIELD STIMULATION, BETA,GAMMA-METHYLENE ATP AND ACETYLCHOLINE
THE EFFECTS OF BAY K-8644 AND NIFEDIPINE ON THE RESPONSES OF RAT URINARY-BLADDER TO ELECTRICAL-FIELD STIMULATION, BETA,GAMMA-METHYLENE ATP AND ACETYLCHOLINE
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DOI：
10.1111/j.1476-5381.1990.tb12736.x
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发表时间：
1990-10-01
影响因子：
7.3
通讯作者：
BURNSTOCK, G
中科院分区：
文献类型：
--
作者：
BO, X;BURNSTOCK, G
1Bay K 8644(0.33 NM至1微米)显著增强β，γ-亚甲基三磷酸腺苷(β，γ-MeATP，10微米)和电场刺激嘌呤能成分(胆碱能反应被阿托品阻断)引起的大鼠膀胱逼尿肌收缩。2Bay K 8644也能增强乙酰胆碱(ACh，10微米)引起的收缩和电场刺激胆碱能成分引起的收缩(用α，β-MeATP脱敏后，嘌呤能反应被阻断)，但幅度小于嘌呤能反应。3硝苯地平(1 NM~3.3微米)可抑制β、γ-MeATPACh和电场刺激引起的所有收缩。然而，虽然对β、γ-MeATP和电场刺激的嘌呤能成分的反应几乎被取消，但对ACh和胆碱能成分的电场刺激的反应中有相当大一部分是硝苯地平抵抗的。4硝苯地平(10 NM)可使Bay K 8644增强β、γ-MeATP、ACh和电场刺激反应的浓度效应右移。在大于1微米的浓度下，贝8644抑制收缩。5结论：电压敏感钙通道在大鼠膀胱P2x-嘌呤受体介导的嘌呤能兴奋反应的机械作用中起重要作用，而胆碱能介导的反应对电压敏感钙通道的依赖性较小。
1 Bay K 8644 (0.33 nM to 1 .mu.M) greatly increased the contractions of rat urinary bladder detrusor muscle induced by .beta.,.gamma.-methylene ATP (.beta.,.gamma.-MeATP, 10 .mu.M) and by electrical field stimulation of the purinergic component (the cholinergic response was blocked by atropine). 2 The contractions induced by acetylcholine (ACh, 10 .mu.M) and by electrical field stimulation of the cholinergic component (the purinergic response was blocked following desensitization by .alpha.,.beta.-MeATP) were also potentiated by Bay K 8644, although to a lesser extent than the purinergic responses. 3 Nifedipine (1 nM to 3.3 .mu.M) inhibited all the contractions induced by .beta.,.gamma.-MeATP ACh and electrical field stimulation. However, while the responses to .beta.,.gamma.-MeATP and electrical field stimulation of the purinergic component were almost abolished, a substantial proportion of the responses to ACh and electrical field stimulation of the cholinergic component were nifedipine resistant. 4 The concentration-effect for the potentiation by Bay K 8644 of the responses to .beta.,.gamma.-MeATP, ACh and electrical field stimulation were shifted to the right by nifedipine (10 nM). At concentrations greater than 1 .mu.M, Bay 8644 inhibited contraction. 5 It is concluded voltage-sensitive calcium channels play an important role in the excitatory mechanical action of P2x-purinoceptor-mediated purinergic responses in the rat urinary bladder, while cholinergic-mediated responses are less dependent on such channels.