摘要比较环孢素A(CsA)转换为雷帕霉素(Rapa)后与CsA长期作用对移植肾大鼠睾丸功能和组织形态学的影响。方法 采用标准的肾移植模型方法进行原位左肾移植,即将Fisher大鼠的供肾移植给Lewis雄性大鼠,36只大鼠分为CsA转换为Rapa组(R组,n=10)、CsA持续使用组(A组,n=10)、CsA撤离组(B组,n=8)和控制对照组(C组,n=8),另接受Lewis大鼠供肾的Lewis同系移植鼠作为同系移植组(T组,n=6)。术后前4组大鼠均给予CsA( 1.5 mg·kg-1·d-1)灌胃至第10天,术后11d至7周R、A、B3组大鼠给予CsA(10 mg·kg-1·d-1)灌胃,术后8周至24周R组改用Rapa(0.5 mg·kg-1 ·d-1)灌胃,A组仍持续使用CsA,B组则改用生理盐水(10 ml·kg-1·d-1),C组大鼠术后11d至24周、T组术后至24周均一直予以生理盐水灌胃。术后24周时处死动物,抽血测睾酮、卵泡刺激素和黄体生成素值,并计算睾酮/黄体生成素比率。记录各组大鼠右侧睾丸的质量,光镜下随机测量曲细精管直径并采用量化的组织学评分标准评估睾丸的组织学损伤;R组、A组和T组随机选取2例睾丸标本应用透射电镜行超微结构检查。结果 R组大鼠血清睾酮水平比T组、A组降低[(0.85±0.09)μg/L比(1.05±0.17) μg/L、(0.94±0.13)μg/L,均P＜0.05],其余组间比较差异均无统计学意义。卵泡雌激素、黄体生产素各组间差异无统计学意义。T组睾酮/黄体生成素比值均高于R、A、B、C4组,R组最低(0.59±0.03)。A、B、R、C组大鼠右侧睾丸质量和平均曲细精管直径比T组明显降低,R组下降最为明显。R、A、B、C组大鼠的睾丸组织学损伤评分比T组均升高。电镜检查R组睾丸组织Leydig细胞线粒体肿胀、内质网扩张和Sertoli细胞的细胞器显著减少;A组Leydig细胞内质网扩张和Sertoli细胞的细胞器减少;而T组睾丸组织的超微结构未发现明显异常。结论 与单纯持续使用CsA相比,CsA转换为Rapa长期作用并未引起移植肾大鼠睾丸的功能损伤,但导致了更严重的组织学损伤。

abstractsObjective To investigate the long-term effects of cyclosporine A(CsA) to rapamycin (Rapa) conversion on testicular function and morphology in rat models of kidney transplantation. Methods Left orthotopic renal transplantation in rats was performed using standard model approach, namely, using Fisher rats as donor and male Lewis rats as recipient. Thirty-six Lewis rat models were randomized into the Rapa group (group R, n=10), CsA continuous use group (group A, n=10), CsA withdrawal group (group B, n=8) and control group (group C, n=8). In addition, the Lewis rats receiving donor Lewis rat kidney were assigned into a syngeneic transplantation group (group T, n=6). Immediately after surgery, Groups R,A, B and C were subjected to gavage of CsA (1.5 mg·kg-1 ·d-1) till day 10. Thereafter, groups R, A and B were given a larger dose of CsA ( 10 mg· kg-1· d-1 ) gavage from day 11 to week 7. From weeks 8 to week 24,CsA was converted to Rapa (0.5 mg· kg-1 ·d-1 ) in group R and to normal saline (10 ml· kg-1· d-1 ) in group B,and remained unchanged in group A. Gavage of normal saline was also given to group C from day 11 to week 24, and to group T immediately after surgery till week 24. At week 24 after surgery, the rats were sacrificed and phlebotomized for determination of testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH). Moreover, the testosterone/LH ratio was calculated. The weights of right testis were then recorded in every group. Thereafter, the seminiferous tubule diameter (STD) was randomly measured under light microscope, and a quantitative histological score criteria was used to evaluate the histological injury of testis. Every two specimens of testis were randomly selected from groups R, A and T for examination of ultrastructure using transmission electron microscopy. Results The serum level of testosterone in group R was lowered as compared with group T, group A [(0.85±0.09) μg/L vs (1.05±0.17) μg/L, (0.94+0.13) μg/L,all P＜0.05]but was not significantly different among the other groups. There were no differences in FSH and LH among the five groups. The testosterone/LH ratio was highest in T group and lowest in R group (0.59±0.03). Compared with T group, the weights of right testis and mean STD in groups R, A, B and C were significantly reduced, and were lowest in group R. Groups R, A, B and C had increased histological injury scores as compared with group T. Under electron microscopy, group R showed edematous mitochondria,dilated endoplasmic reticulum in Leydig cells and significantly reduced organelles in Sertoli cells, and group A showed edematous mitochondra in Leydig cells and reduced organelles in Sertoli cells, while group T did not show any abnormalities in ultrastructure of testis tissues. Conclusion Compared with continuous use of CsA, the long-term effect of CsA to Rapamycin conversion may not compromise the function of testis but can lead to more severe histological injury.