Cryopreservation Extenders Affect Calcium Flux in Bovine Spermatozoa During a Temperature Challenge

摘要: Bovine spermatozoa are commercially cryopreserved by diluting the cells in media, known as extenders, followed slow cooling and freezing. Previous work has shown that this process of cryopreservation alters cells' ability to control divalent calcium (Ca2+) movement. This study evaluated effect a brief exposure common extenders on bovine during subsequent rewarming. Three fresh ejaculates from each three bulls were split incubated for 30 minutes at 25 degrees C milk extender or phosphate-buffered saline (PBS) (control); other similarly egg yolk-Tris (EYT) PBS. Spermatozoa washed fluorescent Ca2+ indicator, indo-1 acetoxymethyl ester, was used monitor internal Ca(2+)-free PBS over continuous temperature gradient (15 minutes), 5 (32 rewarming (25 minutes). Milk reduced initial percentage missing acrosomes EYT improved viability acrosome morphology compared controls; only immediatetly increased Ca2+. The rate uptake greater EYT-exposed than controls (P < 0.05). During cooling, all 0.01), it continued increase 15 C. C, declined.(ABSTRACT TRUNCATED AT 250 WORDS)