细菌脂多糖急性暴露对小鼠睾丸组织的损害作用

Acute exposure to lipopolysaccharide impairs testicular tissue in male mice

目的探讨细菌脂多糖(lipopolysaccharide,LPS)急性暴露对小鼠睾丸组织的损害作用。方法 30只健康成年CD-1雄性小鼠被随机分入对照组和LPS组。LPS处理组小鼠经腹腔注射给予LPS(1 mg/kg),对照组给予等容积生理盐水。LPS处理后不同时点(3 h、6 h、12 h和24 h)分批剖杀小鼠。称量睾丸重量并计算脏器系数;采用HE染色观察睾丸病理组织学损害;采用放射免疫法检测小鼠血清睾酮含量;采用免疫组化法标记3β-羟基类固醇脱氢酶(3β-hydroxysteroid dehydrogenase,3β-HSD),以观察睾丸间质细胞数量的变化。结果 LPS处理后12 h和24 h小鼠的睾丸重量和睾丸系数均明显高于对照组(均有P<0.05);处理后12 h和24 h小鼠睾丸内生精上皮结构破坏,生精细胞数量减少;LPS处理后3 h、6 h和12 h小鼠血清睾酮水平明显下降(F=5.24,P=0.004);LPS处理对小鼠睾丸间质细胞的数量无明显影响。结论单次腹腔注射LPS(1 mg/kg)可引起小鼠睾丸组织病理学损伤、降低血清睾酮含量。

Objective To investigate the effects of lipopolysaccharide （LPS） on testicular histopathology and ser- um testosterone levels in male mice. Methods The CD-1 male mice were randomly divided into control group and LPS group, and the number of mice in each group was 6 and 24, respectively. Mice in LPS group were intraperitoneally （ i. p. ） injected with LPS （ 1 mg/kg）, while mice in control group were i.p. injected with normal saline. At different time points （3, 6, 12 and 24 h） after LPS treatments, mice were killed in batches. The weight of testis was measured, and then the organ coefficient of testis was calculated. HE staining was conducted to observe histopathological damage in testis. Serum testosterone was measured by RIA; 3 ^-HSD was detected by immunohistochemistry to estimate the number of Leydig cells. Results At 12 and 24 h after LPS exposure, testicular weight and coefficient were significantly increased （both P 〈 0.05 ）. Moreover, histopathological damage, as determined by a decrease in the number of germ cells, was observed in testicular seminiferous epithelium at 12 and 24 h after LPS treatment. In addition, the levels of serum testosterone were sig- nificantly decreased at 3, 6 and 12 h following LPS administration （ F = 5.24, P = 0. 004）. No significant difference was ob- served in the number of testicular Leydig cells between LPS-treated mice and controls. Conclusions A single dose of LPS at 1 mg/kg causes pathological damage in testis and reduces the levels of serum testosterone in male mice.