Steers William D
Rev Urol. 2002;4 Suppl 3(Suppl 3):S17-25.
Penile erection occurs in response to cavernous smooth muscle relaxation, increased blood flow to the penis, and restriction of venous outflow. These events are regulated by a spinal reflex relying on visual, imaginative, and olfactory stimuli generated within the central nervous system (CNS) and on tactile stimuli to the penis. Drugs can have a facilitatory or inhibitory effect either on the nerves regulating this reflex or on the cavernous smooth muscle. A balance between contractile and relaxant factors governs flaccidity/rigidity within the penis. Drugs that raise cytosolic calcium either prevent or abort erection. Conversely, drugs that lower cytosolic calcium relax smooth muscle and can initiate penile erection. Efficacy in treating erectile dysfunction (ED) with phosphodiesterase inhibitors, especially type 5; alpha-adrenergic-receptor antagonists; and dopamine agonists exploit these mechanisms within the penis or CNS. Recent advances in our understanding of the pharmacology of penile erection are being translated into effective therapies for ED.
阴茎勃起是由海绵体平滑肌松弛、阴茎血流量增加以及静脉流出受限引起的。这些过程由一种脊髓反射调节，该反射依赖于中枢神经系统（CNS）内产生的视觉、想象和嗅觉刺激以及对阴茎的触觉刺激。药物可对调节该反射的神经或海绵体平滑肌产生促进或抑制作用。收缩和舒张因子之间的平衡决定了阴茎的疲软/勃起状态。提高胞质钙水平的药物会阻止或中止勃起。相反，降低胞质钙水平的药物会使平滑肌松弛并可引发阴茎勃起。磷酸二酯酶抑制剂，尤其是5型；α-肾上腺素能受体拮抗剂；以及多巴胺激动剂在治疗勃起功能障碍（ED）方面的疗效利用了阴茎或CNS内的这些机制。我们对阴茎勃起药理学认识的最新进展正在转化为治疗ED的有效疗法。
