Effect of GnRH (Lecirelinum) on selected quality parameters of rabbit ejaculate | Vplyv GnRH (Lecirelínu) na vybrané kvalitatívne ukazovatele semena králikov

The aim of this study was to evaluate the effect of two concentrations of GnRH in insemination doses on selected quality parameters of rabbits ejaculate in vitro. Insemination doses (ID) were diluted to a concentration of 50 x 106 spermatozoa in ID (0.5 ml). Subsequently, ID were divided into 3 samples (control - C, experiment 1, experiment 2). Implementor GnRH (Lecirelinum - commercial product Supergestran, Ferring Pharmaceuticals, the Czech Republic) was added to experimental insemination dose samples at concentrations as follows: experiment 1 to 0.2 ml (5 mg) GnRH - ID and experiment 2 to 0.3 ml (7.5 mg) GnRH - ID. The experimental samples were compared with the control sample. For the assessment of sperm motility, CASA apparatus was used (Computer-Assistend Sperm Analysis) - system SpermVision (MiniTüb, Tiefenbach, FRG) with a microscope Olympus BX 51 (Olympus, Japan). The monitored sperm parameters were as follows: motility (%), progressive motility (%), velocity (micro m per s), curvilinear velocity of movement (micro m per s) and beat per cross frequency. In the experimental samples (experiment 1,2) increase in the level of sperm motility values was detected in time periods of 1 and 3 hours (1 hour-C 47.30 plus minus 7.99%, experiment 1 86.39 plus minus 5.60%, experiment 2 72.48 plus minus 3.80%, 3 hours - 57.09 plus minus 23.36%, experiment 1 89.42 plus minus 2.41%, experiment 2 63.92 plus minus 12.65%) and decrease over a period of 6 hours (C 64.65 plus minus 8.60%, experiment 1 35.26 plus minus 5.22%, experiment 2 50.08 plus minus 8.27%). Progressive sperm motility within time periods of 1 and 3 hours showed similar trend as sperm motility (1 hour - C 30.50 plus minus .35%, experiment 1 79.18 plus minus 6.58%, experiment 2 59.85 plus minus 6.03%; 3 hours - C 42.06 plus minus 22.69%, experiment 1 to 82.31 plus minus 3.64%, experiment 2 to 44.45 plus minus 12.01 %) and decreased over a period of 6 hours (C 56.34 plus minus 8.88%, experiment 1 23.36 plus minus 5.95%, experiment 2 39.07 plus minus 11.17%). Sperm velocity in experiment 1 reached after 1 hour plus minus 82.26 micro m per s, after 3 hours 68.40 plus minus 3.20 micro m per s, after 6 hours 58.21 plus minus 3.89 micro m per s; in experiment 2 was after 1 hour 62.00 plus minus 4.33 micro m per s, after 3 hours 44.37 plus minus 9.19 micro m per s and after 6 hours 52.73 plus minus 9.10 micro m per s, in control group after 1 hour 71.86 plus minus 8.19 micro m per s, after 3 hours 62.35 plus minus 7.89 micro m per s and after 6 hours 73.93 plus minus 8.18 micro m per s. The effect of GnRH under in vitro conditions may very significantly compared with results obtained in vivo.