title: Effect of caffeine and kallikrein on cryo-preserved human spermatozoa.
abstract: Preservation of human semen in liquid nitrogen causes a significant impairment of sperm motility. Ejaculated human spermatozoa show an increased motility in the presence of caffeine, a phosphodiesterase inhibitor, and pancreatic kallikrein (EC 3.4.21.8), a kinin-producing proteinase. Hence, the effect of both substances on post-thaw motility, fructose consumption, and cervical mucus penetration of cryo-preserved human spermatozoa was investigated. The results indicate that both substances stimulate the motility of freshly ejaculated spermatozoa and also improve the motility pattern of cryo-preserved human spermatozoa, thus offering a possible means of improving the quality of freeze-preserved human semen.
mesh_terms: D002110:Caffeine / Q000494:pharmacology*; D002582:Cervix Mucus; D005632:Fructose / Q000378:metabolism; D006801:Humans; D007610:Kallikreins / Q000494:pharmacology*; D008297:Male; D012662:Semen Preservation; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects* / Q000378:metabolism
chemical_list: D005632:Fructose; D002110:Caffeine; D007610:Kallikreins