151 Comparison of prostanoid concentrations in pig plasma and follicular fluid

Isoprostanes (IsoP) and prostaglandins (PG) have important roles within reproduction but are also produced during oxidative stress, thus their use as biomarkers is currently inconclusive. Prostaglandins have been studied in pigs, but there is limited information on IsoP concentration in the follicular environment. In this pilot study, prostanoids including IsoP, PG, and their metabolites were evaluated in pig plasma (P) and follicular fluid (FF) to identify differences. It is hypothesised that specific prostanoids would differ between P and FF. Finishers (21–24 wk; n = 29) had ad libitum access to food and water in group housing under University of Adelaide Ethics S-2022–049. Four days before slaughter, blood was collected into chilled EDTA tubes and centrifuged (1500g, 10 minutes, 4°C). Supernatant P was stored at −80°C until analysis. Ovarian stimulation (PG600) was induced after blood collection. Recovered ovaries were maintained at 31°C in 0.9% saline during transport. Fluid aspirated from preovulatory follicles (>8 mm) on both ovaries was pooled for each female before centrifugation (1000g, 5 minutes, 4°C); supernatant was stored at −80°C until analysis. Prostanoids were quantified in samples using liquid-chromatography tandem mass-spectrometry. Prostanoid data for P and FF were compared using a one-sided paired t-test. Prostanoid data were compared to follicle number with Pearson correlation. Alpha was set to 0.05. Data are presented as mean ± standard error in Table 1. Plasma concentrations of six prostanoids significantly differed from those in FF. Ent-7(RS)-F2t-dihomo IsoP correlated with follicle number (P = 0.034; R = −0.395). Prostanoid 5-F2t-IsoP is a biomarker for oxidative stress while 8-F3t-IsoP is associated with TH1 macrophage response. Neuroprostanes are present in seminal plasma and capable of inducing capacitation in human spermatozoa. Therefore, prostanoid markers could be a novel approach to understand follicular development. Further studies are required to determine if the identified prostanoids are accurate predicators of oocyte quality.