ABSTRACT
Effect of four calcium salts, three calcium antagonists, calcium ionophore (A 23187) and calmodulin was studied in vitro on the motility and viability of ejaculated normal human spermatozoa at different time intervals. Effect of calcium salts was also studied on the oligoasthenospermic samples with an original motility of 10 to 30 per cent. Calcium salts were found to improve the sperm motility by 6 to 16 per cent and this may be due to a direct excitatory influence and a protective action of calcium on the spermatozoa since the viability was also improved by 4 to 11 per cent in these cases. A similar improvement in motility (8 to 11%) and viability (5 to 9%) was observed in hypokinetic samples also, Calcium antagonists inhibited the sperm motility and viability significantly. Diltiazem was the most potent drug in this respect, the reduction in motility being by 11 to 22 per cent and in viability by 6 to 14 per cent, after 30 sec of incubation. Calcium ionophore and calmodulin were found to be more potent than calcium antagonists to produce a dose-dependent decrease in sperm motility and viability. The results confirm that ionized calcium plays an important role in the regulation of sperm motility. Although intracellular concentration of calcium may be a better determinant physiologically, the manipulation of extracellular levels in a critical range may promote the sperm motility, viability and other vital functions. This has a potential use in situations like artificial insemination, in vitro fertilization and semen banking. Calcium ionophores and calmodulin need further investigation for a possible use as vaginal spermicides.