Maggi C A, Santicioli P, Geppetti P, Patacchini R, Frilli S, Astolfi M, Fusco B, Meli A
Pharmacology Department, A. Menarini Pharmaceuticals, Florence, Italy.
Neurosci Lett. 1988 Apr 22;87(1-2):163-7. doi: 10.1016/0304-3940(88)90163-2.
Capsaicin (10 microM) induced a tetrodotoxin (TTX)-resistant release of substance P (SP)- and calcitonin gene-related peptide (CGRP)-like immunoreactivity (LI) from muscle strips of the guinea pig isolated urinary bladder. A second application of capsaicin had no effect, indicating a specific effect on sensory nerves (desensitization). In functional experiments, capsaicin produced a phasic contraction of isolated bladder strips. This response was TTX-resistant, exhibited desensitization and was specifically antagonized by [D-Pro4, D-Trp7.9, Phe11] SP(4-11) a SP antagonist which also reduced, at a similar extent, the contraction induced by exogenous SP. These findings provide direct neurochemical and functional evidence for a transmitter role for a SP-like peptide(s) from peripheral sensory terminals in the guinea pig urinary bladder.
辣椒素（10微摩尔）可诱导豚鼠离体膀胱肌条释放对河豚毒素（TTX）不敏感的P物质（SP）和降钙素基因相关肽（CGRP）样免疫反应性物质（LI）。再次应用辣椒素则无作用，表明其对感觉神经有特异性作用（脱敏）。在功能实验中，辣椒素可使离体膀胱条产生阶段性收缩。该反应对TTX不敏感，表现出脱敏现象，并且可被[D-脯氨酸4，D-色氨酸7.9，苯丙氨酸11] SP（4-11）特异性拮抗，[D-脯氨酸4，D-色氨酸7.9，苯丙氨酸11] SP（4-11）是一种SP拮抗剂，它也能以相似程度减弱外源性SP诱导的收缩。这些发现为豚鼠膀胱外周感觉神经末梢中类似SP的肽作为神经递质的作用提供了直接的神经化学和功能证据。
