Whole-Transcriptome Profiling of Ovarian Tissues in Gilts with Normal Estrus and Follicular Cyst-Associated Anestrus.

Autologous platelet concentrates (APCs) are regenerative blood-derived products prepared from autologous blood and enriched in platelets and bioactive mediators involved in tissue healing and regeneration. Based on their leukocyte and fibrin content, APCs are generally classified into four categories: pure platelet-rich plasma (P-PRP), leukocyte- and platelet-rich plasma (L-PRP), pure platelet-rich fibrin (P-PRF), and leukocyte- and platelet-rich fibrin (L-PRF) (, ). Platelet-rich plasma (PRP), the most widely used APC, is a plasma fraction obtained by centrifugation of autologous blood that contains platelet concentrations above physiological whole-blood (WB) levels (). The intrinsic hematological profile of platelet concentrates—rather than platelet number alone—is increasingly recognized as a key determinant of the biological performance and therapeutic efficacy of PRP. In veterinary medicine, substantial interindividual variability in platelet characteristics complicates the standardization of PRP products, and the interpretation of hematologic measurements (). This variability is influenced by physiological factors such as age, sex, body condition, physical activity and reproductive status, all of which can modulate platelet structure and composition. In the present study, PRP is characterized exclusively in hematological terms, focusing on platelet-related variables that describe its structural phenotype. This approach provides a pragmatic and clinically accessible framework to investigate variability in platelet profiles, while recognizing that it represents only one dimension of PRP characterization and does not capture functional or biochemical properties. Sex is a relevant source of variation in PRP hematological characteristics. Human studies report sex-dependent differences in PRP growth factor content and platelet activation (), largely driven by hormonal regulation. Sex-related hormonal status also influences leukocyte subpopulations and immune cell profiles in whole blood, changes that may persist after PRP preparation and contribute to variability in PRP composition. Comparable findings in horses (, ) and dogs () indicate that sex influences platelet morphology, composition, and related indices across species.