Evaluación de dos diluyentes para la criopreservación de semen de caballos de la raza criollo colombiano

The effects of photobiomodulation on the improvement of sperm parameters: A review study

The prevalence of male infertility has become a significant clinical concern worldwide, with a noticeable upward trend in recent times. The rates of fertilization and subsequent development of embryos are dependent on many parameters associated with the quality and viability of sperm. Photobiomodulation (PBM) is a promising approach with a great potential for translational applications in the treatment of spermatozoa exhibiting low quality and motility. In this study, a comprehensive analysis of the existing literature, specifically examining the mechanisms of action of PBM has been presented. Our objective was to enhance knowledge in the field of laser light therapy in order to promote the usage of irradiation in clinical settings in a more effective way. Within the realm of reproductive science, the utilization of PBM has been employed to enhance the metabolic processes, motility, and viability of spermatozoa. This is attributed to its advantageous effects on mitochondria, resulting in the activation of the mitochondrial respiratory chain and subsequent synthesis of ATP. This therapeutic approach can be highly advantageous in circumventing the reliance on chemical substances within the culture medium for spermatozoa while also facilitating the viability and motility of spermatozoa, particularly in circumstances involving thawing or samples with significant immotility.

Irradiating frozen-thawed stallion sperm with red-light increases their resilience to withstand post-thaw incubation at 38 °C

The aim of this study was to evaluate whether red-light stimulation increases the longevity and resilience of cryopreserved stallion sperm to withstand post-thaw incubation for 120 min. Sixteen frozen straws of 0.5 mL from eight stallions were used. Samples were cryopreserved, thawed through incubation at 38 °C for 30 s and divided into the control and samples exposed to red-light using a triple LED photo-activation system (wavelength: 620-630 nm). Three irradiation protocols consisting of different light-dark-light intervals (1-1-1, 2-2-2 and 3-3-3 min) were tested. Sperm quality parameters were analyzed immediately after light-stimulation (0 min) and after 120 min of incubation at 38 °C. Sperm motility was evaluated using a Computerized Semen Analysis System (CASA), and flow cytometry and different fluorochromes were used to evaluate the integrity and lipid disorder of plasma membrane, mitochondrial membrane potential and intracellular levels of peroxides and superoxides. Irradiation significantly increased the percentages of spermatozoa with high mitochondrial membrane potential (1-1-1 pattern) and the intracellular levels of peroxides (2-2-2 pattern) at 0 min. In addition, sperm kinematic parameters (2-2-2 and 3-3-3 patterns) and percentages of viable spermatozoa with low membrane lipid disorder (3-3-3 pattern) were significantly higher in irradiated samples than in the control at 120 min. Our results indicate that red-light stimulation could help increase the resilience of frozen-thawed stallion sperm to withstand post-thaw incubation at 38 °C for 120 min and that these effects rely on the irradiation pattern. Further research should evaluate whether light-stimulation could also have a positive on fertility rates after artificial insemination.