Way Amy L, Killian Gary J
Almquist Research Center, Department of Dairy and Animal Science, The Pennsylvania State University, University Park 16802, USA.
J Androl. 2002 May-Jun;23(3):352-7.
Identification of norepinephrine (NE) within the microenvironment of the bovine oviduct suggests a potential role for catecholamines in the events surrounding fertilization. Previous studies have shown that the catecholamines capacitate and induce the acrosome reaction in spermatozoa from several species. The current project was undertaken to investigate the role of catecholamines in bovine sperm capacitation and the acrosome reaction. Freshly ejaculated bovine spermatozoa were incubated in NE (0-1000 ng/mL) and induced to acrosome-react with lysophosphatidylcholine (LPC). Additionally, spermatozoa capacitated with heparin were incubated with NE (0-1000 ng/mL) to assess its ability to induce the acrosome-reaction in capacitated spermatozoa. Concentrations of NE were chosen on the basis of physiological concentrations previously determined for bovine oviductal fluid. NE at concentrations of 10 and 20 ng/mL capacitated bovine spermatozoa after 2 hours of incubation. Additionally, spermatozoa incubated for 2 hours with heparin were induced to acrosome-react with 10 and 20 ng/mL NE. Interestingly, higher concentrations of NE inhibited both capacitation and the acrosome reaction. Incubating spermatozoa with dopamine or epinephrine did not result in capacitation or the acrosome reaction, suggesting that the action of NE was specific to that catecholamine. The ability of NE to capacitate or induce the acrosome reaction appears to be dependent on the presence of another membrane-destabilizing factor. Although adrenergic receptors have not been identified on spermatozoa from any species, the action of NE on spermatozoa may be a receptor-mediated event. This study suggests a possible function for oviductal catecholamines in sperm preparation prior to fertilization.
在牛输卵管微环境中鉴定出去甲肾上腺素（NE），这表明儿茶酚胺在受精相关事件中可能发挥作用。先前的研究表明，儿茶酚胺可使几种物种的精子获能并诱导顶体反应。当前项目旨在研究儿茶酚胺在牛精子获能和顶体反应中的作用。将新鲜射出的牛精子在NE（0 - 1000 ng/mL）中孵育，并用溶血磷脂酰胆碱（LPC）诱导其发生顶体反应。此外，将用肝素获能的精子与NE（0 - 1000 ng/mL）孵育，以评估其诱导获能精子发生顶体反应的能力。NE的浓度是根据先前测定的牛输卵管液生理浓度选定的。孵育2小时后，浓度为10和20 ng/mL的NE使牛精子获能。此外，用肝素孵育2小时的精子被10和20 ng/mL的NE诱导发生顶体反应。有趣的是，较高浓度的NE抑制了获能和顶体反应。用多巴胺或肾上腺素孵育精子不会导致获能或顶体反应，这表明NE的作用对该儿茶酚胺具有特异性。NE使精子获能或诱导顶体反应的能力似乎取决于另一种膜不稳定因子的存在。尽管尚未在任何物种的精子上鉴定出肾上腺素能受体，但NE对精子的作用可能是受体介导的事件。这项研究表明输卵管儿茶酚胺在受精前精子准备过程中可能具有作用。
