The concentrations of cytokines in seminal plasma (SP) fluctuate over time in healthy males, weakening their practical usefulness as diagnostic tools. This study evaluated the relevance of intra-male variability in SP cytokines and to what extent the period of the year when ejaculate is collected contributes to such variability. Thirteen cytokines (GM-CSF, IFNγ, IL-1α, IL-1β, IL-1ra, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, and TNFα) were measured using the Luminex xMAP® technology for 180 SP samples of ejaculate collected over a year from nine healthy and fertile boars. The SP samples were grouped into two annual periods according to decreasing or increasing daylight and ambient temperature. Intra-male variability was higher than inter-male variability for all cytokines. All SP cytokines showed concentration differences between the two periods of the year, showing the highest concentration during the increasing daylength/temperature period, irrespective of the male. Similarly, some cytokines showed differences between daylength/temperature periods when focusing on their total amount in the ejaculate. No strong relationship (explaining more than 50% of the total variance) was found between annual fluctuations in SP-cytokine levels and semen parameters. In conclusion, the period of the year during which ejaculates were collected helps explain the intra-male variability of SP-cytokine levels in breeding boars.

中文翻译：

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雄性射精收集的时期有助于精浆细胞因子的年度男性内部变异。

在健康男性中，精浆（SP）中细胞因子的浓度会随时间波动，从而削弱了其作为诊断工具的实用性。这项研究评估了SP细胞因子中男性内部变异的相关性，以及一年中射精的收集在多大程度上促进了这种变异。十三种细胞因子（GM-CSF，IFNγ，IL-1α，IL-1β，IL-1ra，IL-2，IL-4，IL-6，IL-8，IL-10，IL-12，IL-18和使用LuminexxMAP®技术测量了一年中从九个健康可育公猪中收集的180 SP射精样品的TNFα）。根据日光和环境温度的降低或升高，将SP样品分为两个年度。所有细胞因子的男性内部变异性均高于男性内部变异性。所有SP细胞因子在一年的两个时期之间均表现出浓度差异，在日间/温度升高的时期内显示最高浓度，而与男性无关。同样，某些细胞因子在射精中表现出不同的昼间温度/昼夜温差。SP细胞因子水平的年度波动与精液参数之间未发现强关系（解释了总差异的50％以上）。总之，一年中收集射精的时间有助于解释种公猪中SP细胞因子水平的男性内部差异。当关注射精中的总量时，一些细胞因子在日间/温度周期之间显示出差异。SP细胞因子水平的年度波动与精液参数之间未发现强关系（解释了总差异的50％以上）。总之，一年中收集射精的时间有助于解释种公猪中SP细胞因子水平的男性内部差异。当关注射精中的总量时，一些细胞因子在日间/温度周期之间显示出差异。SP细胞因子水平的年度波动与精液参数之间未发现强关系（解释了总差异的50％以上）。总之，一年中收集射精的时间有助于解释种公猪中SP细胞因子的男性内部变异性。