Glutamic oxaloacetic transaminase released from chicken spermatozoa during freeze-thaw procedures

Abstract

The feasibility of using glutamic oxaloacetic transaminase (GOT) released from chicken spermatozoa for evaluation of freeze-thaw damage and the optimum concentration of glycerol on the basis of GOT release were examined. There was a highly significant correlation (-.88) between sperm motility in media containing various concentrations of glycerol and GOT activity in extracellular media after freeze-thawing. This indicates that GOT activity in the supernatant of frozen-thawed semen may be useful as an indicator for frozen-thawed injury of chicken spermatozoa. The amounts of GOT released from spermatozoa after 20 min of glycerol equilibration at 5 C gradually increased from 1 to 18% glycerol. The GOT activity in the extracellular medium after freeze-thawing was lowest at 10% glycerol. To estimate GOT leakage from spermatozoa during the freeze process, except glycerol equilibration, the amounts of GOT just before freezing were subtracted from the amounts of GOT after freeze-thawing. The minimum difference between GOT leakage before and after freeze-thawing was shown to be at 16% glycerol.