Effects of incubation at 4 C on calcium uptake and acrosin activity in turkey spermatozoa.

ABSTRACT

Turkey semen was diluted 11 with a phosphate diluent (Clemson Turkey Semen Diluent) containing radioactively labeled calcium-45 (45Ca) and stored in in vitro at 25 or 4 C to determine the effects of cold-storage on spermatozoa 45Ca permeability. In addition, acrosin activity of semen stored 24 hr at 4 C was compared with that of fresh diluted semen at 25 C. Cold-stored spermatozoa immediately sequestered 45Ca at an exponential rate until the 3 hr disintegrations per min/10(9) spermatozoa equalled that of spermatozoa stored 24 h at 4 C. Washing the spermatozoa after 3 hr incubation reduced the 45Ca of spermatozoa stored at 25 C but not at 4 C. Acrosin activity of spermatozoa diluted 11 with CTSD and stored at 4 C for 24 hr was 1.74 times greater than for fresh sperm held 1 hr at 25 C. These results suggest that cooling turkey spermatozoa causes an intracellular influx of calcium ions that may be associated with acrosin formation.