Bernabé Jacques, Clément Pierre, Denys Pierre, Alexandre Laurent, Giuliano François
Pelvipharm Laboratories, CNRS, 91190 Gif-sur-Yvette, France.
Biol Reprod. 2007 Oct;77(4):717-22. doi: 10.1095/biolreprod.107.060921. Epub 2007 Jun 20.
Synchronized activation of autonomic and somatic divisions of the nervous system respectively destined to the seminal tract, including the bladder neck and the pelvi-perineal striated musculature, is necessary for anterograde ejaculation. We aimed at investigating the role of intermesenteric nerves (IMNs) in ejaculation in anesthetized rats. Electrical stimulation of intact IMNs and distal and proximal stumps of the sectioned IMN were tested in isoflurane-anesthetized male rats. Electrical stimulation of the intact IMN was also applied to rats with acute spinal transection at the T8 level. The effects of IMN electrical stimulation on emission and expulsion phases of ejaculation were evaluated by measuring seminal vesicle pressure (SVP) and bulbospongiosus (BS) muscle contractions, respectively. IMN electrical stimulation could induce SVP increase and rhythmic contractions of BS muscle concomitantly with expulsion of the seminal plug. When compared with intact IMN electrical stimulation, the occurrence of ejaculation and rhythmic BS muscle contractions, but not SVP increase, was reduced in response to electrical stimulation of the distal stump of the sectioned IMN. In comparison to intact IMN electrical stimulation, the occurrence of ejaculation and rhythmic BS muscle contractions was not significantly modified, whereas the increase in SVP was diminished when the proximal stump of the sectioned IMN was stimulated. Spinalization abolished ejaculation and rhythmic BS muscle contraction but did not impair SVP increase. It is concluded that both afferents conveyed by IMN and relaying supraspinally and efferents of IMN are involved in IMN electrical stimulation-induced ejaculation. We propose that the IMN electrical stimulation paradigm can be used to investigate physiological and pharmacologic aspects of ejaculation.
分别支配包括膀胱颈和盆腔 - 会阴横纹肌在内的生殖道的自主神经系统和躯体神经系统的同步激活，对于顺行射精是必要的。我们旨在研究肠系膜间神经（IMNs）在麻醉大鼠射精中的作用。在异氟烷麻醉的雄性大鼠中测试了完整IMNs以及切断的IMN的远端和近端残端的电刺激。还将完整IMN的电刺激应用于T8水平急性脊髓横断的大鼠。通过分别测量精囊压力（SVP）和球海绵体肌（BS）收缩来评估IMN电刺激对射精的排出和射出阶段的影响。IMN电刺激可诱导SVP升高和BS肌肉的节律性收缩，并伴有精栓排出。与完整IMN电刺激相比，切断的IMN远端残端的电刺激导致射精和BS肌肉节律性收缩的发生率降低，但SVP升高未受影响。与完整IMN电刺激相比，切断的IMN近端残端受到刺激时，射精和BS肌肉节律性收缩的发生率没有明显改变，而SVP升高减弱。脊髓横断消除了射精和BS肌肉的节律性收缩，但不影响SVP升高。结论是，IMN传导的传入神经以及脊髓上中继和IMN的传出神经都参与了IMN电刺激诱导的射精。我们提出，IMN电刺激范式可用于研究射精的生理和药理学方面。
