Fang Yi, Zhong Rongzhen, Sun Xuezhao, Zhou Daowei
Jilin Provincial Key Laboratory of Grassland Farming, Northeast Institute of Geography and Agoecology, Chinese Academy of Sciences, Changchun, Jilin 130062, China; Laboratory Animal Center, Jilin University, Changchun, Jilin 130062, China.
Jilin Provincial Key Laboratory of Grassland Farming, Northeast Institute of Geography and Agoecology, Chinese Academy of Sciences, Changchun, Jilin 130062, China.
Theriogenology. 2018 Feb;107:127-133. doi: 10.1016/j.theriogenology.2017.11.005. Epub 2017 Nov 10.
Although salt-tolerant plants can be used to combat dryland salinity, these plants contain high concentrations of salt (NaCl), which may have deleterious effects if fed to livestock. Twenty-four Merino rams (9 mo of age) with similar body weight were equally allocated to two groups and fed a normal- or high-salt diet (0.5 and 12% NaCl, respectively) for 3 mo. Rams fed the high-salt diet had lower live weight gains, higher water intake, smaller testes (466 ± 48.4 vs 604 ± 51.1 g) and reductions (P <0.05) in spermatogenesis, ejaculate volumes (0.89 ± 0.18 vs 1.24 ± 0.15 mL/ejaculate), sperm concentration (14.3 ± 2.05 vs 22.3 ± 2.33 × 10 sperm/mL) and DNA integrity (DNA fragmentation rate: 5.85 ± 1.09 vs 1.13 ± 0.14%) compared to controls. For in vitro fertilization, although cleavage percentage was not significantly affected, hatching rate was lower (30.8 ± 3.81 vs 52.8 ± 4.08%, P <0.05) for sperm from rams on the high-salt diet. Furthermore, the 12% salt diet decreased plasma concentrations of metabolic (leptin and insulin) and sex (T, FSH and LH) hormones, but did not affect the plasma renin-angiotensin system (RAS) component (REN, Ang II, ACE and ALD). Regarding components of the testicular RAS, the 12% salt diet decreased (P <0.05) expression of REN, Ang II and AT2 mRNA, although ACE and AT1 were unaffected. Furthermore, the 12% salt diet decreased (P <0.05) mRNA expression of key genes for spermatogenesis (Hsp70, c-kit and Cyclin A), and sex hormone receptors (AR, FSHR, LHR, CYP11A1 and CYP17A1), but there were no significant effects on key enzymes (LDH, SDH, AKP and ATPase) in the testis. In conclusion, the high-salt diet reduced ram reproductive performance; we inferred that changes in testis RAS may have had an important role in these reproductive defects.
虽然耐盐植物可用于对抗旱地盐碱化，但这些植物含有高浓度的盐（氯化钠），如果喂给牲畜可能会产生有害影响。将24只体重相近的9月龄美利奴公羊平均分为两组，分别饲喂正常盐或高盐日粮（分别含0.5%和12%的氯化钠），持续3个月。饲喂高盐日粮的公羊体重增加较低，饮水量较高，睾丸较小（466±48.4克对604±51.1克），精子发生、射精量（0.89±0.18毫升/次射精对1.24±0.15毫升/次射精）、精子浓度（14.3±2.05×10⁶精子/毫升对22.3±2.33×10⁶精子/毫升）和DNA完整性（DNA碎片化率：5.85±1.09%对1.13±0.14%）均降低（P<0.05）。在体外受精方面，虽然卵裂率没有受到显著影响，但高盐日粮公羊的精子孵化率较低（30.8±3.81%对52.8±4.08%，P<0.05）。此外，12%的盐日粮降低了代谢（瘦素和胰岛素）和性激素（睾酮、促卵泡激素和促黄体生成素）的血浆浓度，但不影响血浆肾素-血管紧张素系统（RAS）成分（肾素、血管紧张素II、血管紧张素转换酶和醛固酮）。关于睾丸RAS的成分，12%的盐日粮降低了（P<0.05）肾素、血管紧张素II和AT2 mRNA的表达，尽管血管紧张素转换酶和AT1不受影响。此外，12%的盐日粮降低了（P<0.05）精子发生关键基因（热休克蛋白70、原癌基因c-kit和细胞周期蛋白A）以及性激素受体（雄激素受体、促卵泡激素受体、促黄体生成素受体、细胞色素P450 11A1和细胞色素P450 17A1）的mRNA表达，但对睾丸中的关键酶（乳酸脱氢酶、琥珀酸脱氢酶、碱性磷酸酶和ATP酶）没有显著影响。总之，高盐日粮降低了公羊的繁殖性能；我们推断睾丸RAS的变化可能在这些生殖缺陷中起了重要作用。
