镉对雄性大鼠脊髓下腰段运动神经元的影响  

EFFECTS OF CHRONIC ALTERNATING CADMIUM EXPOSURE ON LOWER LUMBAR SPINAL MOTONEURONS IN MALE RATS

作　　者：许舸[1] 徐晨[1] 

机构地区：[1]重庆医科大学电子显微镜室,重庆400016

出　　处：《中国组织化学与细胞化学杂志》2007年第5期569-574,共6页Chinese Journal of Histochemistry and Cytochemistry

摘　　要：目的研究镉对成年雄性大鼠脊髓下腰段SNB和DLN运动神经元超微结构和雄激素受体(AR)表达的影响。方法成年雄性大鼠腹腔内反复小剂量注射氯化镉(0.5mg/kg体重和1.0mg/kg体重交替注射)及丙酸睾酮(TP)500μg皮下注射后,采血测定血清睾酮含量,取脊髓L5-6节段进行SNB和DLN运动神经元AR免疫组化及光密度(OD)分析,透射电镜观察SNB和DLN运动神经元超微结构,采用原子吸收石墨炉法测定脊髓镉含量。结果染镉后脊髓内镉含量升高,血清睾酮水平在染镉30d时明显下降。染镉7d、10d、15d,神经元核AR免疫染色平均OD值降低,TP皮下注射2h,AR平均OD值无明显升高;染镉30d,AR平均OD值进一步降低,TP皮下注射2h,AR平均OD值增加,但是只达到单纯染镉7d、10d、15d时水平。染镉后,神经元超微结构无明显改变。结论镉可以蓄积在成年大鼠脊髓内,导致SNB和DLN运动神经元功能损伤,可能与镉所致性功能障碍有关。Objective To investigate the effects of cadmium （Cd） on ultrastructure and expression of androgen receptors （AR） in the SNB and DLN spinal motoneurons of adult male rats. Methods Adult male Wistar rats were treated intraperitoneally with cadmium chloride （CdCl2） at the alternate dose of 0. 5 and 1 mg/kg body weight and subcutaneously with 500μg testosterone propionate （TP） . The changes of ultrastructure, androgen receptor （AR） immunochemistry and mean optical density （OD） of AR immunoreactivity in the nuclei of SNB and DLN were studied; serum testosterone levels and cadmium accumulation in the spinal cord were measured. Results The content of Cd in spinal cord increased significantly after Cd exposure. With repeated Cd administration, an obvious decrease was detected in serum testosterone levels on the 30th day. In SNB and DLN motoneurons, AR mean OD in nuclei was reduced 7, 10, 15 days after Cd treatment. No recovery was seen after TP injection. AR mean OD in nuclei was decreased significantly 30 days later and recovered partly after TP injection. No obvious change was seen in SNB and DLN motoneurons at the ultrastructural level after Cd administration. Conclusion With alternate, low dose Cd exposure, Cd can deposit in the spinal cord of male rats. It may cause functional change in SNB and DLN motoneurons, which may be related to the sexual dysfunction induced by Cd.

关 键 词：镉 脊髓 运动神经元 大鼠 性功能障碍 

分 类 号：R992[医药卫生—毒理学] R741.02[医药卫生—药学]