n-6/n-3多不饱和脂肪酸营养失衡对小鼠精子发生的影响

Dietary Imbalance of n-6/n-3 PUFAs Affects Spermatogenesis in C57/B6 Mice

目的:探讨n-6/n-3多不饱和脂肪酸营养失衡对小鼠精子发生的影响。方法:健康的30只C57/B6雄鼠随机分为对照组(CON)、高脂组(HF)、花生四烯酸组(HF+AA)。喂食16周,做合笼实验并记录致孕率,通过精子动力分析仪检测小鼠精子活力和数量的变化,用Elisa试剂盒测血清中睾酮和甘油三酯水平。通过病理组织染色观察小鼠睾丸组织的形态学变化。利用Realtime-PCR的方法检测小鼠睾丸中Dazl基因表达水平的变化。结果:高脂组、花生四烯酸组与对照组相比精子活力[(16±0.01;12.33±2.83 vs72.2±12.73)%,P<0.001],精子数量[(7.5±1.13;6±0.14 vs 13.87±0.35)million/m L,P<0.001],致孕率[(28.57;14.29 vs 78.57)%,P<0.001]及血清睾酮含量[(0.35±0.14;0.27±0.07 vs 3.51±0.7)ng/m L,P<0.001]均显著性降低。高脂组、花生四烯酸组与对照组相比,血清中甘油三酯的含量显著增高[(0.74±0.04;0.74±0.04 vs 0.45±0.04)mmol/L,P<0.001]。病理组织染色观察到花生四烯酸组小鼠睾丸组织出现了明显异形,曲细精管内部的初级精母细胞明显缺失,管腔中从初级精母细胞到精子的发生过程出现了变异,精子的数量也显著性下降。参与精子生成过程中的减数分裂前的有丝分裂增殖期、精原细胞的发育等过程的Dazl基因在高脂组和花生四烯酸组小鼠睾丸中的表达量与对照组相比显著降低(0.87±0.05;0.65±0.03 vs 1.07±0.04,P<0.05)。

Objective：To observe the effects of dietary imbalance n-6/n-3 poly unsaturated fatty acids （PUFAs） on spermatogenesis in mice.Methods：Thirty healthy C57/B6 male mice were randomly divided into the control group （CON）,high fat group （HF）,arachidonic acid group （HF＋AA）.After 16 weeks of feeding,sperm motility and counts were evaluated with computer-aided sperm analysis （CASA）.The pregnancy rate were recorded after mating experiments.Serum testosterone and TG levels were tested by Elisa Kit.HE staining was conducted to observe morphology oftesticular.The expression level of Dazl within testis was tested by Realtime-PCR.Results：After 16 weeks dietary intervention,sperm motility[（16± 0.01;12.33± 2.83 vs 72.2± 12.73） %,P〈0.001],sperm counts [（7.5± 1.13;6± 0.14 vs 13.87± 0.35） million/mL,P〈0.001],the pregnancy rate [（28.57;14.29 vs 78.57） %,P〈0.001] and the serum testosterone level[（0.35 ± 0.14;0.27± 0.07 vs 3.51 ± 0.7） ng/mL,P〈0.001] of the high fat group and arachidonic acid group were significantly decreased compared with those of the control group （P〈0.05）.The serum TG level of the high fat group and arachidonic acid group were higher than that of the control group[（0.74± 0.04;0.74± 0.04 vs 0.45± 0.04） mmol/L,P〈0.001].HE staining showed that the testis tissue of the arachidonic acid group showed abnormal morphology,the primary spermatocytes were significantly absent in the seminiferous tubules,the development process from primary spermatocytes to sperm appeared mutated,and the number of spermatozoa also significantly decline.The expression of Dazl,which have a critical role in the development of spermatogonia and entry into the meiosis of the mitotic proliferation period,was significantly reduced in the testis of the high fat group and arachidonic acid group compared with that of the control group （0.87± 0.05;0.65± 0.03 vs 1.07± 0.04,P〈0.05）.Conclusions：Dietary imbalance ofn-6/n-3 PUFAs can induce spermatogenesis dysfunction,that inturn contributes to male subfertility.