葛根素对糖尿病大鼠睾丸的保护作用

Protective effect of puerarin on testis in diabetic rats

目的:探讨葛根素对糖尿病大鼠睾丸的保护作用及其机制。方法:雄性SD大鼠随机分成6组:正常对照组,糖尿病模型组,葛根素高(160mg·kg-1)、中(120mg·kg-1)、低(80mg·kg-1)剂量治疗组,氨基胍(100mg·kg-1)治疗组;各组大鼠每天腹腔注射相应药物1次,正常对照组及糖尿病模型组腹腔注射等体积丙二醇。治疗12周后,透射电镜下观察睾丸的形态学改变,用生化、免疫学方法测定睾丸组织中一氧化氮(NO)、内皮素-1(ET-1)、降钙素基因相关肽(CGRP)、丙二醛(MDA)的含量及一氧化氮合酶(NOS)、诱导型NOS(iNOS)、超氧化物歧化酶(SOD)、Ca2+-ATPase、Na+-K+-ATPase的活性,采用RT-PCR检测睾丸组织内皮型NOS(eNOS)、iNOS、CGRP、ET-1、醛糖还原酶(AR)的基因表达水平。结果:糖尿病组大鼠睾丸组织电镜下主要见到支持细胞与曲细精管基底膜接触面减小、出现空泡,胞浆内内含物形成;NO、CGRP含量及SOD、Ca2+-ATPase、Na+-K+-ATPase活性和eNOS、CGRPmRNA表达明显低于正常对照组(P<0.05或P<0.01),而ET-1、MDA含量及NOS、iNOS活性和iNOS、AR、ET-1mRNA表达明显高于正常对照组(均P<0.01)。经葛根素治疗后,上述改变逆转,与糖尿病模型组比较差异显著(P<0.05或P<0.01),电镜下睾丸组织的形态结构接近于正常组;而葛根素高、中、低剂量治疗组、氨基胍治疗组间差异无显著。结论:葛根素对糖尿病大鼠睾丸具有一定的保护作用,其机制可能与改善睾丸血供及减轻氧化应激损伤有关。

AIM： To investigate the protective effect of puerarin on testis in diabetic rats. METHODS： The male Sprague- Dawley rats were randomly divided into normal control group, diabetic group, high dose puerarin （160 mg/kg）, middle dose puerarin （120 mg/kg）, low dose puerarin （80 mg/kg） treatment groups and aminoguanidine （100 mg/kg） treatment group. Corresponding drugs were intraperitoneal injected once a day. The animals in normal control group and diabetic group were given equal propylene glycol. 12 weeks later, the rats were sacrificed and their testes were collected. Testicular structure was observed under transmission electronic microscope （TEM）. The contents of nitric oxide （NO）, malondialdehyde （MDA） and the activity of nitric oxide synthase （NOS）, inducible nitric oxide synthase （iNOS）, superoxide dismutase（ SOD）, Ca^2 ＋- ATPase and Na^＋ - K^＋ - ATPase in testis homogenate were detected biochemically. The levels of endothelin - 1 （ ET - 1 ） and calcitonin gene - related peptide （CGRP） were also measured by radioimmunoassay. In addition, the mRNA expressions of eNOS, iNOS, CGRP, ET - 1 and AR in testis tissues were determined by reverse transcription polymerase chain reaction （RT- PCR）. RESULTS： The pathologic changes such as cytoplasmic inclusion of sertoli cell and obvious vacuoles between sertoli cells and basal membrane of the contorted seminiferous tubules were observed under TEM in diabetic group. The contents of NO and CGRP, the activities of SOD, Ca^2＋ -ATPase, Na^＋ - K^＋ - ATPase as well as the mRNA expressions of eNOS and CGRP decreased significantly （P 〈 0. 05 or P 〈 0. 01, respectively）. The ET - 1 and MDA levels, the activities of NOS and iNOS, and the mRNA expressions of iNOS, AR and ET - 1 increased obviously （P 〈0. 01, respectively） in diabetic group as compared to those in normal control group. However, in puerarin treatment groups, the above changes were reversed, a significant differences of those were found compared to diabetic group （P 〈 0. 05 or P 〈 0. 01, respectively）. There were plenty of mitochondria, endoplasmic reticulum and more lysosomes in the cytoplasm of sertoli cells, and plain hierarchical tight - junction among sertoli cells, spermatogenic cells and basal membrane of the contorted seminiferous tubules in puerarin treatment groups. The changes of above evidences among different doses of puerarin treatment groups and aminoguanidine treatment group showed no statistic significance. CONCLUSION： Puerarin exerts preventive and remedial effects on the diabetic testis, which may be related to improving the blood supply and relieving oxidative stress damage.