High ambient temperature disrupted the circadian rhythm of reproductive hormones and changed the testicular expression of steroidogenesis genes and clock genes in male mice. (15th January 2020)

• Record Type: Journal Article
• Authors: Li, Zhaojian; Li, Yansen; Ren, Yu; Li, Chunmei
• Is Part Of: Molecular and cellular endocrinology. Volume 500(2020)
• Publication Date: 2020-01-15
• Subjects: Circadian rhythm -- Reproductive hormone -- High ambient temperature -- Steroidogenesis; Endocrinology -- Periodicals; Molecular biology -- Periodicals; Cytology -- Periodicals; Endocrinology -- Periodicals; Hormones -- Periodicals; Endocrinologie -- Périodiques; Cytology; Endocrinology; Molecular biology; Periodicals; 573.4
• DOI: 10.1016/j.mce.2019.110639
• Languages: English
• ISSNs: 0303-7207

Abstract

Abstract: 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. Highlights: Heat exposure altered circadian pattern in rectal temperature and feeding behaviors. Heat exposure from ZT4 to ZT8 advanced the peak serum testosterone from ZT8 to ZT4. Heat exposure increased AR and Star gene expression at ZT4. Heat exposure increased testicular Cyp11a1 and Bmal1 protein level at ZT16. Heat exposure reduced testicular Clock protein level at ZT4.