降钙素基因相关肽在阴茎勃起机制中的作用

The role of CGRP in penile erection

通过实验动物（成年雄性狗）研究肽能神经介质──降钙素基因相关肽（ＣＧＲＰ）在勃起机制中的作用。取动物海绵体平滑肌、阴部内动脉、静脉等组织离体灌注并活体海绵体内注射ＣＧＲＰ，证实对离体组织具有舒张作用，以海绵体平滑肌最强。活体海绵体内注射观察动脉血流量增加，海绵体内压升高，阴茎明显胀大。刺激海绵体神经诱导阴茎勃起检测ＣＧＲＰ水平变化，发现在勃起高峰时，海绵体组织内ＣＧＲＰ增高，面消退期血浆内ＣＧＲＰ升高。从而证实ＣＧＲＰ可导致海绵体平滑肌松弛、减少阻力，增快动脉血流，是促使阴茎勃起的主要神经介质之一。在消退期也可能参与使阻闭静脉的开放，加快回流的作用。

Effects of CGRP on haemedynamics of penile erection were investigated in dogs by RIA, both in vivo and in vitro.In vitro, CGRP caused a different degree of relaxation upon strips of corpus cavernous smooth muscle, internal pudendal artery and vein and penile dorsal vein.CGRP relaxation index in corpus cavernous smooth muscle has been stronger than that in the artery and vein.In vivo, intracavernous injection of CGRP evoked a penile tumescence. Hence, PAF and CCP showed an increase.CGRP concentration of corpus cavernous tissues during erection increased, while CGRP concentration of blood from cavernous space during detumescence increased.Our results point out that CGRP, as a kind of neuromedium, may relax directly the corpus cavernous smooth muscle and the penile artery increasing the blood flow and evoking ponile erection. During detumesecence it might be involved in the opening of occluded venous drainage thus facilitating detumesecence.