Giuliano F, Bernabé J, Brown K, Droupy S, Benoit G, Rampin O
Service d'Urologie, Hôpital de Bicêtre, Faculté de Médecine Paris-Sud, Le Kremlin Bicêtre, France.
Am J Physiol. 1997 Dec;273(6):R1990-7. doi: 10.1152/ajpregu.1997.273.6.R1990.
The role of peripheral parasympathetic and sympathetic pathways was explored in erectile responses elicited by hypothalamic medial preoptic area (MPOA) stimulation in adult male anesthetized rats. Under control conditions, MPOA stimulation reliably elicited erectile responses evidenced by an increase of the intracavernous pressure-to-blood pressure ratio. The erectile response was abolished by 1) acute bilateral section of cavernous or pelvic nerves or cauda equina and 2) chronic lesions of pelvic nerves or cauda equina. Acute section of the hypogastric nerve did not significantly decrease the erectile response. The erectile response was significantly depressed after acute or chronic sections of the paravertebral sympathetic chain at the L4-L5 level or chemical sympathectomy with 6-hydroxydopamine. The decrease due to acute sympathetic chain lesion was reversed by bilateral ligation of the external iliac arteries. Accordingly MPOA stimulation elicits erectile responses via 1) activation of the parasympathetic outflow conveyed by the pelvic and cavernous nerves and 2) activation of neural fibers conveyed by the sympathetic pathways. We propose that sympathetic fibers running in the paravertebral sympathetic chain are responsible for vasoconstriction of nonpenile areas to divert blood to the penis, allowing the dramatic increase of penile arterial inflow required for erection.
在成年雄性麻醉大鼠中，研究了下丘脑内侧视前区（MPOA）刺激引发的勃起反应中，外周副交感神经和交感神经通路的作用。在对照条件下，MPOA刺激可靠地引发勃起反应，表现为海绵体内压与血压比值增加。勃起反应可被以下操作消除：1）海绵体神经或盆神经或马尾的急性双侧切断；2）盆神经或马尾的慢性损伤。腹下神经的急性切断并未显著降低勃起反应。在L4-L5水平进行椎旁交感神经链的急性或慢性切断，或用6-羟基多巴胺进行化学性交感神经切除术之后，勃起反应显著降低。双侧结扎髂外动脉可逆转急性交感神经链损伤所致的反应降低。因此，MPOA刺激通过以下方式引发勃起反应：1）激活由盆神经和海绵体神经传导的副交感神经传出通路；2）激活由交感神经通路传导的神经纤维。我们认为，在椎旁交感神经链中走行的交感神经纤维负责非阴茎区域的血管收缩，从而将血液引流至阴茎，使勃起所需的阴茎动脉血流量显著增加。
