Banihani S, Agarwal A, Sharma R, Bayachou M
Department of Medical Laboratory Sciences, Jordan University of Science and Technology, Irbid, Jordan.
Andrologia. 2014 Aug;46(6):637-41. doi: 10.1111/and.12130. Epub 2013 Jul 3.
Successful cryopreservation for human spermatozoa markedly influences the reproductive outcomes of assisted reproductive technologies. But in spite of its usefulness, cryopreservation significantly decreases sperm quality. l-carnitine has been found to improve the quality of spermatozoa in selected cases with male infertility. Here, we examined the efficacy of l-carnitine in improving sperm motility and vitality and reducing sperm DNA oxidation during cryopreservation. Semen samples from infertile patients (n = 22) were collected and analysed. Cryopreservation medium supplemented with l-carnitine was mixed with the semen at a ratio of 1 : 1 (v/v). The final l-carnitine concentration in each cryovial was 0.5 mg ml(-1) per 5 × 10(6) cell ml(-1) . Controls were cryopreserved without addition of l-carnitine. After 24 h of cryopreservation, thawed sperm samples were analysed for motility, vitality and DNA oxidation. Sperm vitality was assessed by the eosin-nigrosin test, while sperm DNA oxidation was measured by flow cytometry. Addition of l-carnitine significantly improved sperm motility and vitality (P < 0.05) compared with the control. The flow cytometry experiment showed no statistical difference (P > 0.05) in the levels of DNA oxidation between samples and controls. In conclusion, l-carnitine improves human sperm motility and vitality, but has no effect on sperm DNA oxidation after cryopreservation.
成功的人类精子冷冻保存对辅助生殖技术的生殖结果有显著影响。尽管其有用性，但冷冻保存会显著降低精子质量。已发现左旋肉碱在某些男性不育病例中可改善精子质量。在此，我们研究了左旋肉碱在冷冻保存过程中提高精子活力和存活率以及减少精子DNA氧化的功效。收集并分析了不育患者（n = 22）的精液样本。将添加了左旋肉碱的冷冻保存培养基与精液按1:1（v/v）的比例混合。每个冻存管中最终的左旋肉碱浓度为每5×10(6)个细胞/毫升0.5毫克/毫升。对照组在不添加左旋肉碱的情况下进行冷冻保存。冷冻保存24小时后，对解冻后的精子样本进行活力、存活率和DNA氧化分析。通过伊红-黑色素试验评估精子存活率，同时通过流式细胞术测量精子DNA氧化。与对照组相比，添加左旋肉碱显著提高了精子活力和存活率（P < 0.05）。流式细胞术实验表明，样本与对照组之间的DNA氧化水平无统计学差异（P > 0.05）。总之，左旋肉碱可提高人类精子活力和存活率，但对冷冻保存后的精子DNA氧化无影响。
