Acute anomalous high-temperature exposure impacts on mouse ovaries

The purpose of this study is to assess the impact of acute anomalous high-temperature exposure on mouse ovaries, hormone profiles, estrous cyclicity, and folliculogenesis.

Reproductively young CD-1 mice (6-12 weeks old) were housed in temperature-adjustable chambers under control (28 °C) or heat stress conditions (35 °C) for 1 or 4 consecutive days. Ovaries were collected either immediately after exposure or after a 3-week delay period.

Body weights remained unchanged across groups. Ovary weight was significantly reduced immediately following 4 days of heat exposure, while ovary length trended toward a decrease. Serum hormones-AMH, FSH, and progesterone-were not significantly different between groups. All animals cycled at least twice during a 2-week monitoring period. Follicle counts across all follicle stages were also not significantly different between groups.

Short-term exposure to elevated temperature (35 °C) leads to a transient reduction in ovary weight without altering hormone levels, cyclicity, or folliculogenesis. These findings suggest that acute heat stress may primarily affect the ovarian stroma, warranting further investigation into its structural and functional consequences.