Fernández S, Córdoba M
Cátedra de Química Biológica, Instituto de Investigación y Tecnología en Reproducción Animal, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
Reprod Domest Anim. 2014 Dec;49(6):941-6. doi: 10.1111/rda.12410. Epub 2014 Sep 23.
The aim of this research was to study the effect of hyaluronic acid on bovine cryopreserved spermatozoa compared with heparin as regards the variation of capacitation induction, cellular oxidative metabolism and intracellular signal induced by membrane-associated adenylate cyclase to propose hyaluronic acid as a capacitation inductor. Heparin or hyaluronic acid and lysophosphatidylcholine were used to induce sperm capacitation and acrosome reaction, respectively. 2',5'-dideoxyadenosine was used as a membrane-associated adenylate cyclase inhibitor. The highest percentages of capacitated spermatozoa and live spermatozoa with acrosome integrity were obtained by incubating sperm for 60 min using 1000 μg/ml hyaluronic acid. In these conditions, capacitation induced by hyaluronic acid was lower compared with heparin; nonetheless both glycosaminoglycans promote intracellular changes that allow true acrosome reaction in vitro induced by lysophosphatidylcholine in bovine spermatozoa. Oxygen consumption in heparin-capacitated spermatozoa was significantly higher than in hyaluronic acid-treated spermatozoa. With all treatments, mitochondrial coupling was observed when a specific uncoupler of the respiratory chain was added. The inhibition of membrane-associated adenylate cyclase significantly blocked capacitation induction produced by hyaluronic acid, maintaining a basal sperm oxygen uptake in contrast to heparin effect in which both sperm parameters were inhibited, suggesting that the membrane-associated adenylate cyclase activation is involved in the intracellular signal mechanisms induced by both capacitation inductors, but only regulates mitochondrial oxidative phosphorylation in heparin-capacitated spermatozoa.
本研究的目的是研究透明质酸对牛冷冻保存精子的影响，并与肝素在诱导获能变化、细胞氧化代谢以及膜相关腺苷酸环化酶诱导的细胞内信号方面进行比较，以提出透明质酸作为一种获能诱导剂。分别使用肝素或透明质酸和溶血磷脂酰胆碱来诱导精子获能和顶体反应。2',5'-二脱氧腺苷用作膜相关腺苷酸环化酶抑制剂。使用1000μg/ml透明质酸孵育精子60分钟可获得最高百分比的获能精子和顶体完整的活精子。在这些条件下，与肝素相比，透明质酸诱导的获能较低；尽管如此，两种糖胺聚糖都能促进细胞内变化，从而使牛精子在体外由溶血磷脂酰胆碱诱导真正的顶体反应。肝素诱导获能的精子中的氧消耗显著高于透明质酸处理的精子。在所有处理中，当添加呼吸链的特定解偶联剂时，均观察到线粒体偶联。膜相关腺苷酸环化酶的抑制显著阻断了透明质酸诱导的获能，与肝素的作用相反，维持了精子的基础氧摄取，肝素作用下两种精子参数均受到抑制，这表明膜相关腺苷酸环化酶的激活参与了两种获能诱导剂诱导的细胞内信号机制，但仅调节肝素诱导获能精子中的线粒体氧化磷酸化。
