Evaluation of mitochondria in oocytes following ?-irradiation.

ABSTRACT: Standard cytotoxic cancer treatments, such as radiation, can damage and deplete the supply of oocytes stored within the ovary, which predisposes females to infertility and premature menopause later in life. The mechanisms by which radiation induces oocyte damage have not been completely elucidated. The objective of this study was to determine if ?-irradiation changes mitochondrial characteristics in oocytes, possibly contributing to a reduction in oocyte number and quality. Immature oocytes were collected from postnatal day (PN) 9-11 C57Bl6 mice 3, 6 and 24?hours after 0.1?Gy ?-irradiation to monitor acute mitochondrial changes. Oocytes were classified as small (>20?µm) or growing (40-60?µm). Mitochondrial membrane potential was lost in 20% and 44% of small oocytes (~20?µm) at 3 and 6?hours after ?-irradiation, respectively, consistent with the induction of apoptosis. However, mitochondrial mass, distribution and membrane potential in the surviving small oocytes were similar to the non-irradiated controls at both time points. At 24?hours after ?-irradiation, all mitochondrial parameters analysed within immature oocytes were similar to untreated controls. Mitochondrial parameters within growing oocytes were also similar to untreated controls. When mice were superovulated more than 3 weeks after ?-irradiation, there was a significant reduction in the number of mature oocytes harvested compared to controls (Control 18?±?1 vs 0.1?Gy 4?±?1, n?=?6/16 mice, p?

SUBMITTER: Wang Q 

PROVIDER: S-EPMC6934861 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature