Influence of cryoprotectant concentration on cell volume and motility of frozen-thawed fowl spermatozoa

• Published in: Japanese poultry science Vol. 25; no. 5; pp. 268 - 277
• Main Authors: Terada, T. (Hiroshima Univ., Fukuyama (Japan). Faculty of Applied Biological Science), Hashimoto, H, Maeda, T, Watanabe, M, Tsutsumi, Y
• Format: Journal Article
• Language: English
• Published: Japan Poultry Science Association 25.09.1988
• Subjects: cell volume; CELLS; CELLULE; CELULAS; CHEMICALS; CHICKENS; CONGELACION; CONGELATION; cryopreservation; cryoprotectant; DECONGELATION; DESCONGELACION; ESPERMATOZOO; FREEZING; MOUVEMENT; MOVEMENT; MOVIMIENTO; POLLO; POULET; PRODUCTOS QUIMICOS; PRODUIT CHIMIQUE; SPERMATOZOA; SPERMATOZOIDE; THAWING; VOLUME; VOLUMEN
• ISSN: 0029-0254
• DOI: 10.2141/jpsa.25.268

The present study was designed to investigate the changes in motility and cell volume of frozen-thawed fowl spermatozoa under the various concentrations of cyoprotectants, such as glycerol, dimethylsulfoxide (DMSO) and N-methyl-formamide, and to have an insight on their protective mechanisms against freeze-thawing. One volume of pooled semen was diluted with three volumes of a 5.7% glucose solution which contained different levels of each cryoprotectant. The diluted semen was frozen by the pelleting method. The motility and cell volume of the spermatozoa were examined immediately after thawing at 37°C. The cell volume of the spermatozoa was measured using a Coulter counter (Model ZB) attached with a Coulter channelyzer and a super-microcomputer. 1) The distribution pattern of cell volumes of the fresh or frozen-thawed spermatozoa showed a sharp, symmetrical and normal curve. The mode of mean cell volume in fresh spermatozoa was evaluated at 5.2μm3. 2) The highly significant negative correlation was proven between the motility and the cell volume of spermatozoa frozen-thawed in the presence of three kinds of cryoprotectants mentioned above (P<0.01). 3) When spermatozoa were frozen without cryoprotectants mean cell volume of the postthaw spermatozoa decreased significantly as compared with that of unfrozen fresh spermatozoa. 4) With elevation of glycerol level up to 7%, a linear decrease was observed in the mean cell volume of postthaw spermatozoa (minimum volume, 3.7μm3), but the sperm motility increased contrarily. However, when glycerol level was elevated above 7%, the cell volumes of postthaw spermatozoa tended to increase, while the sperm motility decreased. 5) When DMSO and N-methylformamide were used similar effects were observed for both sperm volume and its motility. 6) We presume that the optimum levels of the cryoprotective agents used in the present study facilitate the reduction of intracellular water contents most effectively during freezing to make intracellular ice formation minimum, and consequently provide maximum protection for spermatozoa against freeze-thawing.