BACKGROUND The nerve growth factor (NGF), a member of the neurotrophins family, plays an important role not only in the nervous but also in other non-nervous systems such as the reproductive system. The aim of the paper is to study the in vitro effect of NGF on rabbit sperm functions. METHODS Ten adult rabbit bucks were collected five times, and pooled semen samples have been analysed. NGF was quantified in seminal plasma, and the distribution of NGF receptors (TrKA and p75NTR) in sperm was established. Moreover, the dose-effect of NGF on motility rate and track speed was evaluated. Successively, the effect of the neutralisation of NGF receptors was assessed to verify the specific role of each receptor. Untreated sperm were used as control. RESULTS Our study identified several interesting results: i) We detected NGF in seminal plasma and TrKA and p75NTR in sperm surface. In particular, TrKA is localised in the head and p75NTR in the midpiece and tail of rabbit sperm. ii) Once the optimal dose of NGF (100 ng/mL) was established, its addition affected both kinetics and other physiological traits (capacitation, apoptosis and necrosis) of rabbit sperm. (iii) The neutralisation of TrKA and p75NTR receptors affected sperm traits differently. In particular, sperm speed, apoptosis and capacitation seemed mainly modulated via p75NTR receptor, whereas motile, live cells, necrosis and acrosome reaction were modulated via TrKA. CONCLUSION For the first time, we showed the presence of p75NTR in rabbit sperm. NGF affects kinetic and other physiological traits of rabbit sperm. Most of these changes are modulated by the receptors involved (TrKA or p75NTR). Considering that some seminal disorders in human have been correlated with a lower NGF concentration and no studies have been done on the possible involvement of NGF receptors, these findings also provide new insights on human fertility.

中文翻译：

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神经生长因子对家兔精子主要性状的体外影响

背景技术神经生长因子(NGF)是神经营养素家族的成员，不仅在神经系统中发挥着重要作用，而且在其他非神经系统例如生殖系统中也发挥着重要作用。本论文的目的是研究NGF对家兔精子功能的体外影响。方法 对 10 只成年兔进行五次采集，并对汇集的精液样本进行分析。对精浆中的 NGF 进行定量，并确定精子中 NGF 受体（TrKA 和 p75NTR）的分布。此外，还评估了 NGF 对运动速率和轨迹速度的剂量效应。随后，评估了NGF受体的中和效果，以验证每种受体的具体作用。未经处理的精子用作对照。结果 我们的研究发现了几个有趣的结果： i) 我们在精浆中检测到 NGF，在精子表面检测到 TrKA 和 p75NTR。特别是，TrKA 位于兔精子的头部，p75NTR 位于兔精子的中段和尾部。ii) 一旦确定了 NGF 的最佳剂量（100 ng/mL），其添加就会影响兔精子的动力学和其他生理特性（获能、凋亡和坏死）。(iii) TrKA 和 p75NTR 受体的中和对精子性状的影响不同。特别是，精子速度、细胞凋亡和获能似乎主要通过 p75NTR 受体调节，而活动细胞、活细胞、坏死和顶体反应则通过 TrKA 调节。结论 我们首次在兔精子中发现了 p75NTR 的存在。NGF 影响兔精子的动力学和其他生理特性。大多数这些变化是由相关受体（TrKA 或 p75NTR）调节的。考虑到人类的一些精液疾病与较低的 NGF 浓度相关，并且尚未对 NGF 受体可能参与的研究进行研究，这些发现也为人类生育能力提供了新的见解。