Mahmoud A I, Parrish J J
Department of Meat and Animal Science, University of Wisconsin, Madison 53706, USA.
Mol Reprod Dev. 1996 Apr;43(4):554-60. doi: 10.1002/(SICI)1098-2795(199604)43:4<554::AID-MRD19>3.0.CO;2-Z.
Eight different lectins conjugated to fluorescein isothiocyanate (FITC) were used to screen for sperm plasma membrane changes during in vitro capacitation of bovine sperm. Analysis of lectin binding to sperm was done using flow cytometry. Of the eight lectins, only Triticum vulgaris (wheat germ agglutinin, WGA) binding to sperm was altered with capacitation. Capacitation of bovine sperm by heparin was found to decrease WGA binding to sperm by 78% (P < 0.05). The effect of capacitation by oviduct fluid was next compared with capacitation by heparin for changes in WGA binding to sperm. The effect of inhibiting capacitation with glucose on WGA binding was also determined. WGA-bound sperm were detected by flow cytometry as being present in two fluorescence peaks defined as low fluorescence (A) or high fluorescence (B) intensity. The percentage of sperm in peak A was greater for heparin and oviduct fluid-treated sperm compared to sperm incubated under noncapacitating conditions in only culture medium (P < 0.001). Capacitation with either heparin or oviduct fluid was inhibited by glucose as assessed by the ability of lysophosphatidylcholine (100 micrograms/ml) to induce acrosome reactions. Glucose also reduced the percentage of sperm in peak A for both heparin- and oviduct fluid-treated sperm (P < 0.01). We conclude that heparin or oviduct fluid induced changes on the sperm plasma membrane during capacitation. Binding sites for WGA on sperm were either structurally altered or lost during capacitation.
使用八种与异硫氰酸荧光素（FITC）偶联的不同凝集素来筛选牛精子体外获能过程中精子质膜的变化。使用流式细胞术分析凝集素与精子的结合情况。在这八种凝集素中，只有与精子结合的普通小麦（麦胚凝集素，WGA）在获能过程中发生了改变。发现肝素诱导牛精子获能会使WGA与精子的结合减少78%（P<0.05）。接下来比较了输卵管液诱导获能与肝素诱导获能对WGA与精子结合变化的影响。还确定了葡萄糖抑制获能对WGA结合的影响。通过流式细胞术检测到结合WGA的精子存在于两个荧光峰中，定义为低荧光（A）或高荧光（B）强度。与仅在培养基中于非获能条件下孵育的精子相比，肝素和输卵管液处理的精子中A峰精子的百分比更高（P<0.001）。通过溶血磷脂酰胆碱（100微克/毫升）诱导顶体反应的能力评估，葡萄糖抑制了肝素或输卵管液诱导的获能。葡萄糖还降低了肝素和输卵管液处理的精子中A峰精子的百分比（P<0.01）。我们得出结论，肝素或输卵管液在获能过程中诱导了精子质膜的变化。精子上WGA的结合位点在获能过程中要么结构改变要么丢失。
