High ambient temperature-related male reproduction disruptions are well illustrated across species, the effects on circadian oscillation in reproduction hormones and testicular steroidogenesis remain unclear. Here, we showed the changes in circadian behaviour in rectal temperature, ingestion and serum hormones as well as the testicular oscillations of steroidogenesis genes and clock genes in heat-treated male mice. We observed that daily heat exposure from 11:00 (ZT4) to 15:00 (ZT8) increased the rectal temperature at ZT8 and water intake from ZT4 to ZT8 and decreased the feed consumption from ZT4 to ZT12 (19:00). Serum testosterone levels were arrhythmic after heat exposure, with an increase at ZT4 and a reduce at ZT8. Heat exposure enhanced testicular StAR and AR mRNA transcription at ZT4 and Cyp11a1 protein levels at ZT16. A much higher Clock mRNA level was observed at ZT4 in the testis of heat-treated mice, and the Clock protein content was reduced at ZT4. The Bmal1 protein level in the testis at ZT16 was increased in heat-treated mice. These results suggest that high external environmental temperature changes the circadian rhythms of body temperature and serum reproduction hormones and the testicular oscillations of clock genes and steroidogenesis genes, supporting the hypothesis that high temperatures arrest spermatogenesis by a disrupted reproductive rhythm.

中文翻译：

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高环境温度扰乱了雄性小鼠生殖激素的昼夜节律，改变了睾丸类固醇生成基因和时钟基因的表达。


与高环境温度相关的雄性生殖中断在各个物种中都有很好的说明，但其对生殖激素和睾丸类固醇生成的昼夜节律振荡的影响仍不清楚。在这里，我们展示了热处理雄性小鼠中直肠温度、摄入和血清激素的昼夜节律行为的变化，以及类固醇生成基因和时钟基因的睾丸振荡。我们观察到，每天11:00（ZT4）至15:00（ZT8）的热暴露增加了ZT8的直肠温度和ZT4至ZT8的饮水量，并减少了ZT4至ZT12（19:00）的饲料消耗。热暴露后血清睾酮水平出现心律失常，ZT4 时升高，ZT8 时降低。热暴露增强了 ZT4 的睾丸 StAR 和 AR mRNA 转录以及 ZT16 的 Cyp11a1 蛋白水平。在热处理小鼠的睾丸中，ZT4 处观察到更高的 Clock mRNA 水平，并且 ZT4 处的 Clock 蛋白含量降低。在热处理小鼠中，ZT16 时睾丸中的 Bmal1 蛋白水平有所增加。这些结果表明，外部环境温度高会改变体温和血清生殖激素的昼夜节律，以及时钟基因和类固醇生成基因的睾丸振荡，支持高温通过破坏生殖节律来阻止精子发生的假设。