Reproduction Abstracts

This work was aimed at determining in vivo levels of oxygen (O₂) within the porcine oviduct. 13 gilts (G) and eight sows (S) were used. A left lateral paralumbar laparoendoscopic single-site surgical approach (GelPOINT Advanced, SingleMedical→) was carried out under CO₂ pneumoperitoneum. Laparoscopy manoeuvres allowed pulling up the ovary towards the single-site port and upon visual inspection pigs were assorted into preovulatory (PreO) or postovulatory (PostO) stages. A luminescent O₂ probe coupled to a register unit (Al300, Neofox, Oceanoptics→) was sequentially inserted into the ampulla (Amp) and isthmus (Isth) for a time period of 8–10 min after signal stabilization. Registers were obtained after replacing back the organs -with the probe inserted- into the abdominal cavity. Moderate hypoxia levels were observed within the porcine oviducts (39–85.8 mmHg or 5.13–11.29%). O₂ levels were significantly different for the maturity state (79.0±10.6 vs 51.7±8.4 mmHg for G and S respectively, P<0.001) and the region of the oviduct (71.4±16.7 vs 64.6±16 mmHg for Amp and Isth respectively, P<0.001). While the phase of the estrous cycle did not directly affect the O₂ levels (66.1±14.4 vs 71.4±18.2 mmHg for PreO and PostO respectively, P=0.36), an interaction between the phase of the estrous cycle and the region of the oviduct was observed (P<0.001). The reduced O₂ content within the pig oviduct is consistent with previous results in other mammals. The particular effect of the pig maturity and the oviduct region on the O₂ levels (higher values in G and Amp) may contribute to a better understanding of the role of O₂ on the physiology of the oviduct and should be considered for assisted reproductive techniques. Work supported by project AGL2012-40180-C03-03 (MINECO, Spain).