In both tests, the percentage of motile spermatozoa increased with increasing glycerol concentration. However, the thermoresistance tests differed significantly in their capacity to reveal differences in the proportions of sperm with a normal apical ridge which is an indicator of damage to the acrosomal membrane system. The prolonged incubation of sperm at 37EC caused deterioration and changes in the acrosomes and may also allow a proportion of the sperm to undergo the acrosome reaction, a condition indistinguishable from an abnormal loss of the apical ridge. The new test was superior in its ability to reveal differences in sperm membrane integrity occurring after freezing in the present of different glycerol concentrations. The results show that effective cryopreservation requires simultaneous optimization of freezing and thawing rates and glycerol concentration.
Optimization thus represents a compromise between maintenance of motility and acrosomal integrity.
An increase in one at the expense of the other characteristic reduces fertility. This information is provided as a public service, but we cannot guarantee that the information is current or accurate. Readers should verify the information before acting on it.