Epsilon Open Archive

Abstract

Reproduction may be affected by stressful events changing the female endocrine or metabolic profile. An altered environment during oocyte development could influence the delicate process of oocyte maturation. Here, the effect of simulated stress by media supplementation with blood plasma from sows after adrenocorticotropic hormone (ACTH) administration during the preovulatory period was assessed. Oocytes were matured for 46 h in the presence of plasma from ACTH-treated sows, or plasma from NaCl-treated control sows, or medium without plasma (BSA group). The plasma used had been collected at 36 h and 12 h (± 2 h) before ovulation (for the first 24 h + last 22 h of maturation, respectively). Subsequent fertilisation and embryo development were evaluated. Actin cytoskeleton and mitochondrial patterns were studied by confocal microscopy both in the oocytes and the resulting blastocysts. Nuclear maturation did not differ between treatments. Subtle differences were observed in the actin microfilaments in oocytes; however, mitochondrial patterns were associated with the treatment (P<0.001). These differences in mitochondrial patterns were not reflected by in vitro outcomes, which were similar in all groups. In conclusion, an altered hormonal environment provided by a brief exposure to plasma from ACTH-treated sows during in vitro oocyte maturation, could induce alterations in actin cytoskeleton and mitochondrial patterns in oocytes. However, these changes might not hamper the subsequent in vitro embryo development.