Bernabò N, Tettamanti E, Pistilli M G, Nardinocchi D, Berardinelli P, Mattioli M, Barboni B
Institute of Physiology, Department of Biomedical Science, P.zza Aldo Moro 45, Teramo, Italy.
Theriogenology. 2007 Mar 1;67(4):801-15. doi: 10.1016/j.theriogenology.2006.10.014. Epub 2006 Dec 29.
The aim of this study was to evaluate the effect of an acute exposure to a sinusoidal MF-ELF (50 Hz, 1mT) on the ability of boar mature spermatozoa to acquire the fertilizing competence in vitro. The spermatozoa exposed during the 4h of incubation to the MF-ELF were evaluated for morphological (surface morphology and acrosome integrity) and functional parameters (cell viability, motility, induction of acrosomal reaction, AR, and the ability to in vitro fertilize oocytes). In parallel, the intracellular Ca(2+) levels as well as the major mechanisms of Ca(2+) clearance were assessed: (45)Ca intakes and intracellular Ca(2+) sequestration by analyzing intracellular Ca(2+) elevation induced by thapsigargin or studying mitochondrial function with Mito-Tracker. The MF-ELF exposure did not affect sperm viability and morphology during the first h of incubation when sperm Ca(2+) homeostasis were already compromised. First of all, MF-ELF treated spermatozoa showed resting intracellular Ca(2+) levels significantly lower than those recorded in controls. This result was dependent on a lower extracellular Ca(2+) intake and from the inhibitory role exerted on both intracellular Ca(2+) storages. As a consequence, after 1h of incubation MF-ELF exposed cells displayed a reduced motility, a modest reactivity when coincubated with solubilized zonae pellucidae and a reduction in oocyte penetrating ability. After 2 or 4h of incubation, in addition, signs of morphological damage appeared on plasma membrane and at acrosomal level. In conclusion, MF-ELF influence negatively spermatozoa first by impairing cell Ca(2+) homeostasis then by dramatically affecting sperm morphology and function.
本研究的目的是评估急性暴露于正弦中频-极低频（50Hz，1mT）对公猪成熟精子在体外获得受精能力的影响。对在孵育4小时期间暴露于中频-极低频的精子进行形态学（表面形态和顶体完整性）和功能参数评估（细胞活力、运动性、顶体反应诱导、AR以及体外使卵母细胞受精的能力）。同时，评估细胞内Ca(2+)水平以及Ca(2+)清除的主要机制：通过分析毒胡萝卜素诱导的细胞内Ca(2+)升高或用Mito-Tracker研究线粒体功能来评估(45)Ca摄取和细胞内Ca(2+)螯合。在精子Ca(2+)稳态已经受损的孵育的第一个小时内，中频-极低频暴露不影响精子活力和形态。首先，经中频-极低频处理的精子显示静止细胞内Ca(2+)水平显著低于对照组记录的水平。该结果取决于较低的细胞外Ca(2+)摄取以及对两种细胞内Ca(2+)储存所发挥的抑制作用。因此，孵育1小时后，暴露于中频-极低频的细胞运动性降低，与溶解的透明带共同孵育时反应性适度降低，并且卵母细胞穿透能力降低。此外，孵育2或4小时后，质膜和顶体水平出现形态损伤迹象。总之，中频-极低频首先通过损害细胞Ca(2+)稳态，然后通过显著影响精子形态和功能，对精子产生负面影响。
