睾酮缺乏对高脂饮食小型猪血脂和肝内脂质沉积的影响

目的 探讨睾酮缺乏对高脂饮食小型猪血脂水平和肝脏脂质沉积的影响.方法 取6~7月龄性成熟后的雄性五指山小型猪18只按体重随机分成三组,即不去势组,去势组和去势加睾酮处理组,每组6只.三组动物均采用高脂饲料饲喂12周,每周测定动物体重.采血检测血清睾酮、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)和甘油三酯(TG)水平变化.12周后动物处死,采集肝组织,检测肝脏TG和TC含量.肝组织标本石蜡包埋切片后进行苏木素-伊红染色,观察肝脏病理变化. 结果 (1)高脂饮食诱导后,三组小型猪体重均呈线性增长趋势,不去势和去势加睾酮处理组小型猪的体重略高于去势组小型猪,但三者差异不显著;(2)去势小型猪血清睾酮含量显著减少,但给予外源性睾酮后,睾酮水平恢复;(3)去势显著增加高脂饮食小型猪血清TC,LDL-C和TG水平,但对血清HDL-C水平没有显著影响.睾酮处理后,血清TG,TC和LDL-C水平均显著降低;(4)去势组小型猪肝脏TG和TC含量均显著高于不去势组小型猪,睾酮处理后TG和TC含量显著减少;(5)与不去势组小型猪相比,去势组小型猪肝细胞脂肪变性程度增加,睾酮处理后,去势小型猪肝脂肪变性程度明显减轻.结论 睾酮缺乏加剧高脂饮食诱导小型猪的血脂代谢紊乱,增加肝脏脂质沉积.

Effects of testosterone deficiency on serum lipid levels and hepatic lipid accumulation in miniature pigs fed a high-fat diet

Objective The aim of this study was to explore the effect of testosterone deficiency on serum lipid levels and hepatic lipid accumulation in miniature pigs fed a high-fat diet (HFD). Methods Eighteen sexually mature male Chinese Wuzhishan miniature pigs (6~7 months old) were used in this study. The pigs were divided in three groups (n=6 animals/group) as follows: intact male pigs, castrated male pigs and castrated male pigs with testosterone replacement. They were fed a HFD diet for 12 weeks and body weights were recorded weekly. Serum levels of testosterone, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) were measured. Hepatic TG and TC levels were also determined, and liver tissues were embedded in paraffin and stained with hematoxylin and eosin (H&E). Results (1) The body weights of pigs in each group were found to be linearly elevated over time. Though castrated pigs gained less weight than did pigs in the other groups, no significant differences were found between them. (2) Castration caused a significant decrease in serum testosterone levels in pigs. This effect was recovered by testosterone treatment. (3) Serum levels of TC, LDL-C and TG were significantly increased in castrated pigs. However, castration had no significant effect on serum HDL-C levels. Testosterone treatment reduced the increased serum lipids in castrated pigs. (4) Hepatic TG and TC contents in castrated pigs were also significantly higher than those in other groups of pigs. Testosterone treatment reduced the increased hepatic lipids in castrated pigs. (5) Compared with other groups of pigs, castrated pigs showed increased steatosis. However, testosterone treatment attenuated hepatic steatosis in castrated pigs. Conclusion Testosterone deficiency caused severe dyslipidemia, and increased hepatic lipid accumulation in miniature pigs fed a high-fat diet.