低温联合地塞米松对大鼠睾丸扭转复位后eNOS表达及生精细胞凋亡的影响

目的:探讨低温联合地塞米松对睾丸扭转复位后的保护作用,以及对eNOS表达及生精细胞凋亡的影响。方法:将80只青春期SD大鼠随机分为4组,每组20只。4组大鼠分别扭转左侧睾丸720°2 h,建立单侧睾丸扭转模型,随后各组做如下处理,A组:常温+生理盐水、B组:低温+生理盐水、C组:低温+地塞米松、D组:常温+地塞米松;术后48 h采集睾丸,通过HE染色光镜观察睾丸组织病理学改变、免疫组化法检测eNOS表达、TUNEL法检测睾丸生精细胞凋亡。结果:HE染色光镜下见4组大鼠扭转侧睾丸组织均有不同程度损伤,其中A组睾丸损伤最明显,其余3组扭转侧睾丸得到不同程度保护;睾丸组织eNOS免疫组化检测结果:A组扭转侧(左侧)睾丸组织阳性细胞数及阳性细胞着色强度明显强于B、C、D 3组,差异具有显著性(P<0.05、P<0.01、P<0.01);凋亡细胞染色:细胞核呈深棕黄色或棕褐色,A组扭转侧(左侧)睾丸可见大量生精细胞凋亡,凋亡指数AI(31.12±4.68)明显高于B组(16.58±6.22)(P<0.05)及C(8.60±1.15)、D组(13.52±3.06)(P<0.01)。结论:睾丸扭转复位后的缺血再灌注损伤可导致生精细胞凋亡增加、睾丸生殖能力下降;应用低温联合地塞米松能显著增强睾丸组织的抗损伤能力,较好地保护了扭转复位后睾丸的生精功能。

Effects of hypothermia plus dexamethasone on eNOS expression and spermatogenic cell apoptosis after testicular torsion reduction

Objective: To investigate the protective effects of hypothermia combined with dexamethasone on the testis of rats after testicular torsion reduction and on the expression of eNOS and apoptosis of spermatogenic cells.Methods: We made unilateral testicular torsion models in 80 adolescent male Sprague-Dawley rats by 720° torsion of the left testis,and then randomly divided them into four groups of equal number to be treated with normal temperature + physiological saline(group A),hypothermia + physiological saline(group B),hypothermia + dexamethasone(group C),and normal temperature + dexamethasone(group D).After 48 hours,we collected the testes,observed pathological changes of the testicular tissue by HE staining under the light microscope,determined the expression of eNOS by immunohistochemistry,and detected the apoptosis of spermatogenic cells by TUNEL.Results: HE staining showed different degrees of testicular tissue injury in all the four groups of rats,most obvious in group A,while protective effect was observed in the other three groups.Immunohistochemistry revealed significantly more positive cells and higher positive staining intensity in the torsioned(left) testis in group A than in B(P<0.05),C(P<0.01) and D(P< 0.01).The nuclei were deep brown or brown.Lots of apoptotic spermatogenic cells were seen in the torsioned testis of group A,with a significantly higher apoptosis index(31.12±4.68) than in B(16.58±6.22)(P<0.05),C(8.60±1.15)(P<0.01) and D(13.52±3.06)(P<0.01).Conclusion: Ischemia-reperfusion injury after testicular torsion reduction can increase the apoptosis of spermatogenic cells and decrease testicular reproductivity.Hypothermia combined with dexamethasone can protect the testis from injury as well as the reproductive function of the testis after testicular torsion reduction.