Evaluation of the use of L-carnosine in short-term storage of ram semen with spermatological and flow-cytometric analyzes

Abstract

This study was conducted to investigate the effect of adding different doses of L-carnosine to semen in vitro on the short-term storage of semen. Semen taken from 6 Akkaraman rams was used in the research. Semen taken from each animal was pooled. It was diluted with tris+egg yolk extender containing L-carnosine at different doses (1, 5, 10, 20, 50, 100 and 200 mM) and stored at +4 degrees C for 96 hours. Motility and kinematic parameters, abnormal spermatozoa ratio, HOS (Hypo-osmotic swelling test), pH and flow-cytometric analyzes were performed in all experimental groups every 24 hours (0, 24, 48, 72 and 96 hours) during storage. Oxidative stress parameters were determined at 0 and 96 hours. It was determined that 1, 5, 10, 20 mM L-carnosine doses increased total, progressive and rapid motility, kinematic parameters VCL (Curvilinear velocity), VSL (Straight line velocity), VAP (Average path velocity) values and high mitochondrial membrane potential level during short-term storage. It was also determined that these doses protected membrane integrity, reduced the rate of abnormal spermatozoon, acrosomal damage and low mitochondrial membrane potential level. It was determined that a dose of 200 mM L-carnosine had a toxic effect and negatively affected the parameters [total and progressive motility, VCL, VSL, VAP, ALH (Amplitude of lateral head displacement), HOS Test, viability, acrosomal damage, HMMP (High Mitochondrial Membrane Potential), LMMP (Low Mitochondrial Membrane Potential)]. In conclusion, high doses of L-carnosine (200 mM) in semen extenders are harmful to ram semen characteristics after a short time storage. Moreover, low doses of L-carnosine (1, 5, 10 and 20 mM) supplementation may have beneficial effect on ram semen traits, depending on the time storage.