Substance P (SP) is an undecapeptide encoding the tachykinin 1 (TAC1) gene and belongs to the tachykinin family. SP is widely distributed in the central nervous system and the peripheral nervous system. SP is also produced by nonneuronal cells, such as inflammatory cells and endothelial cells. The biological activities of SP are mainly regulated through the high-affinity neurokinin 1 receptor (NK-1R). The SP/NK-1R system plays an important role in the molecular bases of many human pathophysiologic processes, such as pain, infectious and inflammatory diseases, and cancer. In addition, this system has been implicated in fibrotic diseases and processes such as wound healing, myocardial fibrosis, bowel fibrosis, myelofibrosis, renal fibrosis, and lung fibrosis. Recently, studies have shown that SP plays an important role in liver fibrosis and that NK-1R antagonists can inhibit the progression of fibrosis. NK-1R receptor antagonists could provide clinical solutions for fibrotic diseases. This review summarizes the structure and function of SP and its involvement in fibrotic diseases.

中文翻译：

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P物质和纤维化疾病

物质 P (SP) 是编码速激肽 1 (TAC1) 基因的十一肽，属于速激肽家族。SP广泛分布于中枢神经系统和周围神经系统。SP 也由非神经元细胞产生，如炎症细胞和内皮细胞。SP 的生物活性主要通过高亲和力神经激肽 1 受体 (NK-1R) 进行调节。SP/NK-1R 系统在许多人类病理生理过程的分子基础中发挥着重要作用，例如疼痛、传染性和炎症性疾病以及癌症。此外，该系统还涉及纤维化疾病和过程，例如伤口愈合、心肌纤维化、肠纤维化、骨髓纤维化、肾纤维化和肺纤维化。最近，研究表明SP在肝纤维化中起重要作用，NK-1R拮抗剂可以抑制肝纤维化的进展。NK-1R受体拮抗剂可为纤维化疾病提供临床解决方案。本综述总结了 SP 的结构和功能及其在纤维化疾病中的参与。