Maggi C A, Astolfi M, Santicioli P, Tramontana M, Leoncini G, Geppetti P, Giachetti A, Meli A
Pharmacology Department, A. Menarini Pharmaceuticals, Florence, Italy.
J Urol. 1990 Dec;144(6):1546-9. doi: 10.1016/s0022-5347(17)39796-3.
Thiorphan, a well known inhibitor of 'enkephalinase' (endopeptidase 24.11) potentiated and prolonged the contractile response to substance P (SP) and neurokinin A (NKA) on strips of the guinea-pig isolated urinary bladder and this effect was evident both in presence and absence of the mucosal layer. Thiorphan also enhanced and prolonged the capsaicin-induced contraction in strips from the bladder dome which is thought to be mediated by release of endogenous tachykinins. Exposure to capsaicin produced simultaneous release of SP- and tachykinin-like immunoreactivity both in presence and absence of mucosa. This effect of capsaicin was potentiated by thiorphan. Endopeptidase 24.11 activity was detected in the guinea-pig urinary bladder, being more concentrated in the mucosal than the muscular layer. These findings indicate that endopeptidase 24.11 terminates the activity of tachykinins in the guinea-pig urinary bladder and modulates the intensity of the biological response produced after their release from peripheral endings of sensory nerves.
硫喷妥，一种著名的“脑啡肽酶”（内肽酶24.11）抑制剂，能增强并延长豚鼠离体膀胱条对P物质（SP）和神经激肽A（NKA）的收缩反应，且无论有无黏膜层，这种作用均很明显。硫喷妥还能增强并延长膀胱顶条中辣椒素诱导的收缩，这种收缩被认为是由内源性速激肽的释放介导的。无论有无黏膜，暴露于辣椒素都会同时释放SP和速激肽样免疫反应物质。硫喷妥可增强辣椒素的这种作用。在豚鼠膀胱中检测到了内肽酶24.11的活性，其在黏膜层中的浓度高于肌肉层。这些发现表明，内肽酶24.11可终止豚鼠膀胱中速激肽的活性，并调节速激肽从感觉神经外周末梢释放后产生的生物反应强度。
