Effect of intratesticular platelet-rich plasma application on testicular development and semen quality in rams

Platelet-rich plasma (PRP) is a plasma component containing many growth factors and has been suggested to have reproductive effects. This study was conducted to investigate the effects of intratesticular PRP application on testicular development and semen quality in rams. Thirty-two, 2-month-old Akkaraman male lambs were used in the study. Sixteen lambs were treated with saline (control group) and the other 16 lambs were treated with intratesticular autologous PRP (experimental group). Intratesticular applications were conducted on a monthly basis for a period of ten months, spanning from June to March. In both groups, monthly testosterone, testicular morphometric measurements and spermatic cord Doppler ultrasound measurements were performed between July and April for 10 months. A total of 20 animals from the control and experimental groups underwent castration on a monthly basis. Following this procedure, a series of analyses were conducted on the testes of the castrated animals, including cholesterol, fatty acids, oxidative stress, histological, immunohistochemical and molecular analyses. Erection time, routine spermatological, flow cytometric, cholesterol, fatty acids, oxidative stress, cholesterol, fatty acids, oxidative stress and molecular analyses were performed on semen collected weekly for six weeks (end February - mid April) from a total of 14 animals (seven in each group) accustomed to semen collection. In testicular analyses; significant increases in scrotal thickness in December, testicular length in April, blood flow volume in October, mean GSH, GPx, behenic acid, nervonic acid, mRNA expressions of Catsper2, Catsper4, Kcnj11, TRPM3 and TRPM7, seminiferous tubule diameter, germinal cell layer thickness, protein expressions of TGFβ1, VEGFA, FGF10, PDGFB, FSHR, LHR and LC3II measured by Western blot, VEGF in September and mean VEGF and TGFβ immunoexpressions in September, November and April, however, significant decreases in spermatic cord resistive index, MDA levels and apoptotic Bax protein expression along with an earlier onset of spermatogenic activity were observed in PRP group when compared to control. In semen analyses; significant increasess in total and progressive motility, concentration, HOST, VCL, VSL and VAP values, GPx activity, undecylic acid and palmitic acid ratios, and StAR, HSD3β1, CatSper1, IGF1, TGFβ, VEGF and PDGFR levels in ELISA analyses, mRNA expression of CatSper4 in qRT-PCR analyses and protein expressions of VEGFA, PDGFB, TGFβ1, FGF10 and HSD3β2 in Western blot analyses, however, significant decreases in MDA levels, and mRNA expressions of hsa-miR-29a, hsa-miR-148a, hsa-miR-152, oar-miR-200a, hsa-miR-374, hsa-let-7a, oar-miR-10b and hsa-miR-19b were observed in PRP group when compared to the control. In conclusion, monthly intratesticular application of PRP to rams from 2 months of age for 10 months has a positive effect on testicular development, initiation and maintenance of spermatogenesis, morpho-functional and molecular structure of semen. It is concluded that this effect of PRP is due to the rich growth factors in its content.