The vomeronasal organ (VNO) is an accessory olfactory device related to reproductive behavior. The soft tissue of the tubular organ is composed of sensory/non-sensory epithelia and a highly developed vasculature, which in the latter the dilation and contraction of blood vessels are thought to contribute to pumping in and out luminal fluid or air, like penile erectile tissue. The present histological observation of the murine VNO revealed a more complicated vasculature than previously evaluated ones with large differences along the rostro-caudal axis. An immunohistochemical study for vasoactive substances displayed extremely dense innervation by cholinergic nerves containing nitric oxide synthase and VIP/PHI in the thick smooth muscle layer surrounding venous sinuses at light and electron microscopic levels. Furthermore, the differential distribution of cholinergic nerves and adrenergic nerves may provide a novel insight into the pumping mechanism of VNO.

犁鼻器 (VNO) 是与生殖行为相关的附属嗅觉装置。管状器官的软组织由感觉/非感觉上皮和高度发达的脉管系统组成，在后者中，血管的扩张和收缩被认为有助于泵入和排出管腔液体或空气，如阴茎勃起组织。目前对小鼠 VNO 的组织学观察揭示了比以前评估的更复杂的脉管系统，沿着 rostro-caudal 轴有很大差异。血管活性物质的免疫组织化学研究显示，在光和电子显微镜水平下，静脉窦周围厚厚的平滑肌层中含有一氧化氮合酶和 VIP/PHI 的胆碱能神经具有极其密集的神经支配。此外，