阴茎包皮及包皮系带内SP免疫阳性神经末梢的分布和来源

The distribution and origin of SP immunoreactive nerve terminals in the penile frenulum

目的观察成人阴茎包皮和包皮系带内P物质(substanceP,SP)免疫阳性神经末梢的分布和来源。方法免疫组织化学法观察SP免疫阳性神经末梢的分布,荧光金(fluoro-gold,FG)逆行追踪和SP免疫荧光标记相结合法研究大鼠包皮系带内SP免疫阳性神经末梢的来源。结果成人阴茎包皮及包皮系带内均有密集的SP免疫阳性神经末梢存在,这些神经末梢主要位于表皮基底层,呈树枝状或念珠状分布,大多成束走行。阴茎系带处SP免疫阳性神经末梢的分布密度明显大于阴茎包皮处。FG逆标阳性细胞位于大鼠第六腰髓对应的背根神经节(L6-DRG)和第一骶髓对应的背根神经节(S1-DRG)。阳性细胞大中小不等,大多沿神经束成行排列或散在分布。SP免疫荧光标记细胞大多为中小型,呈深红色。FG/SP双标阳性细胞均为中小型,其数量占FG逆标阳性细胞总数的三分之一。结论SP参与了阴茎包皮及包皮系带感觉信息的传递。大鼠阴茎包皮系带内SP免疫阳性神经末梢源自于L6-DRG和S1-DRG。

Objective To study the distribution and origin of substance P （SP） immunoreactive nerve terminals in the prepuce and frenulum of penis in adult human, Methods The SP-immunoreacfive nerve terminals in the penile frenulum were detected by the method of immunohistochemistry. The fluoro-gold （FG） retrogradely tracing and SP immunofluorescence was used to tracing the origin of SP-immunoreactive terminals in penile frenulum of rats. Results In the prepuce and frenulum of penis, dense SP-immunoreactive nerve terminals were mainly observed in the basal stratum of epidermis distributing in a cluster. These nerve terminals were arborescent and beady in appearance. The density of these nerve terminals is significantly higher in frenulum than that in prepuce. FG retrogradely labeled neurons were localized in L6-DRG and S1-DRG, FG positive-neurons were arranged in rows or spots among nerve bundles. Further FG tracing method combined with SP immunofluorescence indicated that a number of DRG neurons were showed SP-immunoreactive. SP-positive neurons were mainly medium or smallsized, intense immunostained, bright red granules appeared as texas-red fluorescence in the cytoplasm, one third of FG-labeled neurons also have Sp-immunoreactive expression in L6-DRG and S^-DRG respectively. Conclusion SP takes part in transmission of traumatic sensation message in the prepuce and frenulum of penis. SP-immunoreactive nerve terminals in the penile frenulum of rats were originated from peripheral branches of neurons which express SP-positive immunoreaction in L6-DRG and I-DRG.