Munarriz Ricardo, Hwang Jonathan, Goldstein Irwin, Traish Abdulmaged M, Kim Noel N
Department of Urology, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
Urology. 2003 Jul;62(1):187-92. doi: 10.1016/s0090-4295(03)00245-0.
To investigate the direct effect of ephedrine and cocaine on neurogenic contraction of penile trabecular smooth muscle. We also provide three case reports of patients who developed priapism secondary to using either cocaine or nonprescription weight loss formulations containing ephedrine. The use/abuse of cocaine has been associated with priapism. In addition, anecdotal evidence suggests that priapism may result from ephedrine use. However, the effects of cocaine and ephedrine on adrenergic regulation of cavernosal tissue and the potential role of sympathetic dysregulation in the development of priapism have not been studied.
Isolated rabbit penile cavernosal tissue strips in organ bath preparations were subjected to electrical field stimulation (EFS) at varying frequencies (5 to 40 Hz) in the absence or presence of ephedrine (60 microg/mL) or cocaine (10 microM). Tissues were then subjected to EFS every 30 minutes for up to 20 hours.
Ephedrine and cocaine initially caused contractions in cavernosal tissue strips that persisted for several hours. EFS-induced contractions became attenuated over time in tissues treated with ephedrine or cocaine. Eventually, the contractile responses to EFS were not distinguishable from the basal tone, although the tissues remained responsive to exogenous phenylephrine.
Functional activation of alpha-adrenergic receptors on trabecular smooth muscle does not appear to be impaired with prolonged cocaine or ephedrine exposure. However, chronic use of cocaine or ephedrine may deplete norepinephrine from sympathetic nerve terminals, leading to priapism.
研究麻黄碱和可卡因对阴茎小梁平滑肌神经源性收缩的直接作用。我们还提供了三例因使用可卡因或含麻黄碱的非处方减肥制剂继发阴茎异常勃起的患者病例报告。可卡因的使用/滥用与阴茎异常勃起有关。此外，有传闻证据表明阴茎异常勃起可能由麻黄碱的使用导致。然而，可卡因和麻黄碱对海绵体组织肾上腺素能调节的影响以及交感神经调节异常在阴茎异常勃起发生中的潜在作用尚未得到研究。
在器官浴制剂中，对分离的兔阴茎海绵体组织条在有无麻黄碱（60微克/毫升）或可卡因（10微摩尔）的情况下，以不同频率（5至40赫兹）进行电场刺激（EFS）。然后每隔30分钟对组织进行一次EFS刺激，持续长达20小时。
麻黄碱和可卡因最初引起海绵体组织条收缩，持续数小时。在用麻黄碱或可卡因处理的组织中，EFS诱导的收缩随时间减弱。最终，对EFS的收缩反应与基础张力无法区分，尽管组织对外源性去氧肾上腺素仍有反应。
长时间暴露于可卡因或麻黄碱后，小梁平滑肌上α-肾上腺素能受体的功能激活似乎并未受损。然而，长期使用可卡因或麻黄碱可能会使交感神经末梢的去甲肾上腺素耗竭，导致阴茎异常勃起。
