内源性一氧化碳对离体犬阴茎海绵体平滑肌的作用

目的:探讨内源性一氧化碳(CO)对离体犬阴茎海绵体平滑肌作用的影响。方法:利用水浴条件下阴茎海绵体肌条的张力测定技术,用CO合成的关键酶血红素氧合酶(HO)的诱导剂———氯高铁血红素诱导海绵体平滑肌生成内源性CO,观察CO对去氧肾上腺素(PE)诱导收缩的阴茎海绵体肌条作用的影响。结果:氯高铁血红素对10μmol/L PE诱导的肌条收缩具有浓度依赖性的松弛作用,10~100μmol/L氯高铁血红素对平滑肌肌条的松弛效应与空白对照相比明显升高(P<0.01)。用锌原卟啉-Ⅸ(ZnPP-Ⅸ)或亚甲蓝孵育处理后的肌条,氯高铁血红素的舒张作用明显减弱(P<0.01)。结论:内源性CO具有浓度依赖性松弛阴茎海绵体平滑肌的作用,其机制可能是通过CO环磷酸鸟苷途径作用所致。

Effect of Endogenous Carbon Monoxide on the Smooth Muscle Function of Dog Penile Corpus Cavernosum in Vitro

OBJECTIVE: To study the effect of endogenous carbon monoxide (CO) on the smooth muscle function of the dog penile corpus cavernosum in vitro. METHODS: Tissue bioassay was used to measure the corpus cavernosum muscle contraction and relaxation. The production of CO was induced in the corpus cavernosum smooth muscle, and the effect of CO on the penile corpus cavernosum smooth muscle pre-contracted by phenylephrine (PE) was determined. RESULTS: Chlorinous hemoglobin could relax the smooth muscle stripes pre-contracted by 10 micromol/L PE. A dose-dependent relaxation was observed. The relaxation responses by 10 -100 micromol/L chlorinous hemoglobin were significant compared with the control group (P < 0. 01). The pretreatment of the muscle stripes with ZnPP-IX or methylthioninium significantly reduced the relaxing effect of chlorinous hemoglobin (P < 0.01). CONCLUSION: The relaxing effect of endogenous CO on the smooth muscle of the penile corpus cavernosum depends on the concentration of endogenous CO. The underlying mechanism may involve the pathway from CO to cGMP production.