尼古丁对大鼠阴茎海绵体内源性CO浓度及NOS活性的影响

目的:观察尼古丁对成年雄性大鼠阴茎海绵体内源性一氧化碳(CO)浓度及一氧化氮合酶(NOS)活性的影响,探讨吸烟对勃起功能损害的可能机制。方法:40只成年雄性Wistar大鼠分为4组,尼古丁注射1个月组、2个月组、3个月组和对照组,尼古丁注射组尼古丁0.5 mg/(kg.d)皮下分别注射1、2、3个月,对照组注射生理盐水。处理后,取阴茎海绵体,用改良双波长分光光度法检测CO浓度,改良Griess法检测NOS活性。结果:对照组CO浓度为(13.66±0.40)μmol/mg prot,NOS活性为(9.72±0.47)U/mg prot。尼古丁注射1个月,CO浓度和NOS活性分别下降为(12.43±0.56)μmol/mg prot和(8.44±0.69)U/mg prot,显著低于对照组(P均<0.01);尼古丁注射2个月,CO浓度和NOS活性分别下降为(11.41±0.52)μmol/mg prot和(7.53±0.24)U/mg prot,显著低于对照组和尼古丁注射1个月组(P<0.01);尼古丁注射3个月,海绵体CO浓度和NOS活性分别下降为(10.52±0.59)μmol/mg prot和(6.64±0.31)U/mg prot,均显著低于对照组和尼古丁注射1个月、2个月组(P均<0.01)。结论:尼古丁可导致成年雄性大鼠阴茎海绵体内源性CO浓度及NOS活性下降,提示内源性CO及NOS参与吸烟引起勃起功能障碍的病理生理过程。

Nicotine reduces endogenous CO concentration and NOS activity in rat corpus cavernosum

Objective: To observe the effects of nicotine on endogenous carbon monoxide(CO) concentration and nitric oxide synthase(NOS) activity in the corpus cavernosum of adult male rats,and explore the possible mechanism of cigarette smoking affecting erectile dysfunction.Methods: Forty adult male rats were equally divided into three treatment groups to receive subcutaneous injection of nicotine at 0.5 mg/kg pre d for 1,2 and 3 months,and a control group to receive saline only.After treatment,the corpus cavernosum was harvested for detection of CO concentration by modified two-wavelength spectrophotometry and NOS activity by improved Griess measurement.Results: CO concentration and NOS activity were decreased by 9.05 and 13.37%,respectively,after 1 month of nicotine injection(P<0.01),16.47 and 22.5% after 2 months(P<0.01),and 22.99 and 31.74% after 3 months(P<0.01),as compared with(13.664±0.404) umol/mg prot and(9.721±0.470) U/mg prot in the control group.Conclusion: Nicotine can reduce endogenous CO concentration and NOS activity in the corpus cavernosum of adult male rats,which suggests the involvement of endogenous CO and NOS in the pathophysiological process of smoking-induced erectile dysfunction.