脊神经前根对大鼠排尿和勃起功能的选择性支配机制

Selective innervation of sacral anterior rootlets to micturition and erection function in rats

目的探讨脊神经前根小束对sD大鼠膀胱和勃起功能的选择性支配机制。方法成年雄性SD大鼠40只，10只行逆行神经示踪，30只行电生理研究：分别刺激大鼠排尿及勃起反射中枢所在脊髓节段的脊神经前根神经小束，同时记录膀胱内压、尿道灌注压和阴茎海绵体内压的变化。结果SD大鼠排尿和勃起功能的低级中枢主要位于L6、S1脊髓节段，电刺激L6、S1脊神经前根某些小束分别引起膀胱内压、尿道灌注压和阴茎海绵体内压的改变。结论SD大鼠L6、S1脊神经前根小束对膀胱逼尿肌、尿道外括约肌和阴茎海绵体的支配效能不同，通过显微解剖及电刺激可以区别。

Objective To investigate the selective innervation of sacral anterior rootlets to micturition and erection function in SD rats. Methods Forty male SD rats of clean grade, aged 6 weeks old, were selected. Ten rats received a retrograde nerve tract tracing study. Thirty rats were chosen for an electro-physiological study. The L6, S1 spinal cord segment anterior rootlets of anesthetic rats were electrostimulated respectively. The intravesical pressure, urethral perfusion pressure and intracarvernerous pressure were recorded simultaneously and innervation effectiveness was analyzed. Results CB-HRP labeled neurons were observed mainly in L6 and S1 spinal cords. When some anterior rootlets of L6 and S1 were electrostimulated, the intravesical pressure rose gradually, but the urethral perfusion pressure and the intracavernous pressure curve changed slightly ; when other rootlets of the same anterior root were stimulated, the urethral perfusion pressure could reach the peak; while others were stimulated, the intracavernours pressure rose quickly, but there were no great changes in iutravesical pressure and urethral perfusion pressure. Some other rootlets might lead to the simultaneous changes of 2 or 3 above-mentioned pressures. Conclusion The innervations of L6 and S1 anterior rootlets to rats＇ bladder detrusor, external urethral sphincter and penile cavernous body are significantly distinct. Different rootlets may be distinguished by microanatomy and electrostimulation.