Abstract
Twelve ejaculates were collected from 6 adult healthy dromedary camels during the rutting season to study the effect of heparin, caffeine and calcium-ionophore on the induction of capacitation in dromedary spermatozoa. Each semen sample was evaluated (sperm progressive motility % and sperm concentration x 10(6)/mL). Nine ejaculates out of twelve were diluted with Shotor buffer to obtain 15 aliquots of 5-10 x 10(6) motile spermatozoa/9900. Five aliquots were mixed with 10 mu l of heparin in concentrations of 0 control, 10 IU (2.5 mu l/mL), 25 IU (5 mu l/mL), 50 IU (10 mu l/mL) and 100 IU (20 mu l/mL). Caffeine (10 mu l) was added to another 5 aliquots in concentrations of 0 control, 2.5 mM (0.00485g/mL), 5 mM (0.0097g/mL), 10 mM (0.0194g/mL) and 20 mM (0.0388g/mL). The last 5 aliquots were mixed with 10 mu l of calcium-ionophore A23187 in concentrations of 0 control, 0.05 mM (3.75 mu l/mL), 0.1 mM (7.53 mu l/mL), 0.2 mM (14.95 mu l/mL) and 0.3 mM (20 mu l/mL). All aliquots were incubated at 38 degrees C in a 5% CO2 atmosphere and 90% relative humidity for 60 min. Aliquots from replications were taken at 0, 5, 15, 30 and 60 min and evaluated for percentages of sperm motility, live sperm and spermatozoa with reacted acrosomes using eosin nigrosin and Chlortetracycline staining. Results revealed differences in viability indices (VI) between camel semen incubated with calcium-ionophore and both semen incubated with heparin and caffeine. Heparin 100 IU, caffeine 5 mM and calcium-ionophore 0.05 mM were the best capacitating factors. A marked increase existed in B (capacitated and acrosome intact) and AR (capacitated and acrosome reacted) patterns cells accompanied with a large decrease in F pattern (uncapacitated and acrosome intact) cells in aliquots with the capacitating factors than in control. In conclusion, heparin (100 IU), caffeine (5 mM) and calcium-ionophore A23187 (0.05 mM) are convenient capacitating factors for dromedary camels' semen. CTC fluorescent staining technique can be used for assessing capacitation status and acrosome reaction in dromedary camels.