The effect of intraepididymal platelet-rich plasma application on quality and freezeability of ram semen

The high level of damage observed in the quality of ram spermatozoa after freezing is related to the different biochemical structure of the lipid composition of the spermatozoon membrane compared to other species. The complete remodelling of the membrane lipid composition and maturation of spermatozoa occurs during transport to the epididymis. Some growth factors interact with cholesterol and other lipid components. PRP contains high levels of many growth factors. This study was conducted to investigate the effects of intraepididymal PRP administration on semen quality and freezeability in rams. In the study, 12 one-year-old adult Akkaraman rams were divided into two groups, control and PRP, with six rams in each group. In the control group, intraepidididymal 0.9% NaCl was administered every 15 days, while in the PRP group, autologous PRP was administered. During the study period, six semen samples (excluding the time of the first injection, including 15 days after the last injection) were collected from each ram every 15 days using an artificial vagina. After the volume of fresh semen samples was determined, half of them were used for routine spermatological analyses (motility, concentration, kinematics, morphological and membrane integrity) and flow-cytometric analyses (mitochondrial activity, apoptosis, live-dead), oxidative stress, fatty acid and cholesterol analyses. The remaining half of the semen were subjected to freeze-thawing. Routine and flow-cytometric spermatological analyses, oxidative stress, fatty acid, cholesterol and molecular analyses were also performed on the frozen-thawed semen. In comparison to control group, intraepidididymal PRP application increased HOS, total motility, kinematic parameters, high mitochondrial activity, GSH, GPx, catalase, margaric acid, stearic acid, vaccenic acid, nervonic acid, α-linoleic acid and docosapentaenoic acid, and decreased head and total abnormalities, apoptosis, damaged acrosome ratios and MDA levels in fresh semen. Compared to the control group, intraepidididymal PRP application increased HOS, total, progressive, rapid motility, VCL, VSL, VAP ratios and catalase, cholesterol, myristic acid, StAR, HSD3β1, CatSper1, PDGF, PDGFR values and reduced damaged acrosome and MDA levels in frozen-thawed semen. Furthermore, the increments in mRNA expressions of CatSper2, 3, 4, Trpm3, Trpv5 ion channels, oar-miR-3958-3p, oar-miR-125b, and protein expressions of CatSper3, HSD3β2, PDGFB and also reductions in bta-miR-22-3p, rno-miR-494 mRNA expressions and VEGFA, TGFβ1 protein expressions were observed in frozen-thawed semen of PRP group. In conclusion, it was demonstrated that intraepididymal PRP administration to adult rams has a beneficial impact on both the quality and freezeability of semen.