Context Ovarian quiescence can be due to hormonal deficiency usually caused by apoptosis of granulosa cells responsible for oestrogen synthesis. Aim This study evaluated the regenerative effect of platelet rich plasma (PRP) on bovine in vitro models to understand its effect on granulosa cells. Methods Quiescent and healthy ovarian sections were cultured in the presence/absence of PRP for 72 h and, at different times (0, 24, 48 and 72 h), hematoxylin-eosin and immunohistochemical detection of Ki-67 were performed. Additionally, granulosa cells collected from healthy bovine ovaries were stressed with 100 ng/mL of lipopolysaccharide (LPS) in presence/absence of PRP and evaluated at 0, 4, 8 and 24 h for apoptosis by acridine orange and propidium iodide staining. Enzyme-linked immunosorbent assay tests were performed to evaluate oestrogen (E2) and anti-Müllerian hormone (AMH) concentrations on cultures of ovarian slices and granulosa cells. Key results In slides of quiescent ovaries treated with PRP, a marked and widespread positivity to Ki-67 was expressed by 40–60% of the follicular wall cells at 48 h of culture. Levels of E2 and AMH were significantly higher compared to untreated quiescent samples reaching the levels of healthy control samples. PRP counteracted the LPS effect and apoptosis (at 24 h, there were 93.44 ± 3.51% live cells with LPS + PRP compared to 37 ± 1.32% with LPS) and significantly increased concentrations of E2 and AMH. Conclusions PRP can stimulate granulosa cell proliferation and counteract inflammatory processes in vitro. Implications This treatment could improve the reproductive ability of quiescent females.

Best's disease with multifocal lesions is rare. The authors describe four cases of multifocal vitelliform disease. The fluorescein angiographic features of macular and extramacular lesions are considered. Different stages of evolution may be present between central and extramacular lesions.

Persistent post-breeding induced endometritis (PPBIE) is considered a major cause of subfertility in mares. It consists of persistent or delayed uterine inflammation in susceptible mares. There are many options for the treatment of PPBIE, but in this study, a novel approach aimed at preventing the onset of PPBIE was investigated. Stallion semen was supplemented with extracellular vesicles derived from amniotic mesenchymal stromal cells (AMSC-EVs) at the time of insemination to prevent or limit the development of PPBIE. Before use in mares, a dose–response curve was produced to evaluate the effect of AMSC-EVs on spermatozoa, and an optimal concentration of 400 × 106 EVs with 10 × 106 spermatozoa/mL was identified. At this concentration, sperm mobility parameters were not negatively affected. Sixteen susceptible mares were enrolled and inseminated with semen (n = 8; control group) or with semen supplemented with EVs (n = 8; EV group). The supplementation of AMSC-EVs to semen resulted in a reduction in polymorphonuclear neutrophil (PMN) infiltration as well as intrauterine fluid accumulation (IUF; p < 0.05). There was a significant reduction in intrauterine cytokine levels (p < 0.05) for TNF-α and IL-6 and an increase in anti-inflammatory IL-10 in mares in the EV group, suggesting successful modulation of the post-insemination inflammatory response. This procedure may be useful for mares susceptible to PPBIE.