Sato Y, Christ G J
Department of Urology, Laboratory of Molecular and Integrative Urology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Am J Physiol Heart Circ Physiol. 2000 Mar;278(3):H964-70. doi: 10.1152/ajpheart.2000.278.3.H964.
Recent findings indicate a complex role for the medial preoptic area (MPOA) in modulating penile erection. To further investigate this important area we measured changes in intracavernous pressure (ICP) elicited by electrical stimulation of the MPOA and evaluated the contribution of the cavernous nerve to the ICP responses after bilateral transection of the cavernous nerve (CN). In all experiments electrical stimulation was performed unilaterally in anesthetized male rats. Two distinct patterns of ICP response were seen after electrical stimulation of the MPOA: 1) increases in ICP during electrical stimulation (pattern 1, n = 10 rats) and 2) increases in ICP after electrical stimulation was terminated (pattern 2, n = 10 rats). For pattern 1, increases in ICP during stimulation exhibited a stable plateau without contraction of striated penile muscles, and bilateral transection of the CN eliminated the ICP responses. For pattern 2, increases in ICP observed after stimulation were lower, more variable, and accompanied by significant amplitude variations ("peaks"), caused by contraction of striated penile muscles. Bilateral transection of the CN eliminated the pattern 2 ICP response but did not alter striated muscle contraction. Histological studies documented that pattern 1 and pattern 2 responses occurred via electrical stimulation of the anterior and posterior areas of the MPOA, respectively. Thus both responses appear to result from activation of the CN, but the pattern 2 response apparently involves contraction of the striated penile muscles as well.
近期研究结果表明，内侧视前区（MPOA）在调节阴茎勃起中发挥着复杂作用。为进一步研究这一重要区域，我们测量了电刺激MPOA所引发的海绵体内压（ICP）变化，并在双侧切断海绵体神经（CN）后评估了海绵体神经对ICP反应的贡献。在所有实验中，均对麻醉后的雄性大鼠进行单侧电刺激。电刺激MPOA后观察到两种不同的ICP反应模式：1）电刺激期间ICP升高（模式1，n = 10只大鼠）和2）电刺激终止后ICP升高（模式2，n = 10只大鼠）。对于模式1，刺激期间ICP升高呈现稳定平台期，阴茎横纹肌无收缩，双侧切断CN可消除ICP反应。对于模式2，刺激后观察到的ICP升高幅度较小、变化更大，且伴有由阴茎横纹肌收缩引起的显著幅度变化（“峰值”）。双侧切断CN可消除模式2的ICP反应，但不改变横纹肌收缩。组织学研究表明，模式1和模式2的反应分别通过电刺激MPOA的前部和后部区域产生。因此，两种反应似乎均由CN激活所致，但模式2的反应显然还涉及阴茎横纹肌的收缩。
