title: Factors affecting the removal of low-molecular-weight fractions (LMWF) from egg yolk and seminal plasma in extended semen by dialysis: effect on post-thaw sperm survival.
abstract: Three factors affecting dialysis of bovine semen were studied. These factors were (1) dialysis rates of egg yolk, seminal plasma, and glycerol, (2) temperature (37 degrees C, 5 degrees C, and while cooling from 37 to 5 degrees C), and (3) dialysis ratios between retentate and dialysate (1:1, 1:10, 1:20, 1:50, and 1:100). Ninety percent of the low-molecular-weight fraction (LMWF) from seminal plasma, egg yolk, and glycerol was removed from the retentate in a 2-hr period at 5 degrees C, and only slight changes were detected after the third hour of dialysis. Temperature affected dialysis and was faster at 37 degrees C. It was also found that a 1:20 dialysis ratio was sufficient to obtain 90% clearance of the LMWF. The effect of sperm dilution ratio, dialysis ratio, and exchange of the LMWF from egg yolk and/or seminal plasma for buffer systems was also studied. An improvement in post-thaw motility of spermatozoa (P less than 0.05) was obtained when the LMWF from both seminal plasma and egg yolk were replaced. A third experiment was conducted to study the effect of different combinations between the buffer systems, TEST and Na citrate, in the dialysate. The results indicated that a 1:1 combination of iso-osmotic solutions (320-325 mOsm/Kg, pH 7.0) between these two buffers, with 5% glycerol (v/v), yielded significant (P less than 0.05) sperm post-thaw motility as compared with the individual use of TEST-glycerol or Na citrate-glycerol. Dialyzed samples also yielded sperm post-thaw motility higher than that of the nondialyzed samples. Colloidal materials in the dialysate did not affect survival of spermatozoa.
mesh_terms: D000818:Animals; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D003956:Dialysis / Q000379:methods; D004530:Egg Yolk; D005615:Freezing; D008297:Male; D008970:Molecular Weight; D012661:Semen / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology* / Q000187:drug effects; D014020:Tissue Extracts / Q000494:pharmacology; D014021:Tissue Preservation / Q000379:methods*
chemical_list: D014020:Tissue Extracts