کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5796330 | 1554392 | 2011 | 5 صفحه PDF | دانلود رایگان |
The maintenance of motility, viability and acrosomal integrity of ram spermatozoa for an extended period of time after cryopreservation is important for achieving high pregnancy rates, when using frozen-thawed semen. The most frequently used cryoprotectant is glycerol, which has to be used at low concentrations (under 4%), due to its potential toxicity. The primary objective of this study was to determine the combined effect of sub-optimal glycerol inclusion and cholesterol-loaded cyclodextrin (CLC) in a Tris-based diluent on ram spermatozoal longevity and acrosomal integrity during in vitro incubation, after cryopreservation. Ram semen was treated with 0 or 2 mg CLC/100 Ã 106 cells in Tris-based diluents containing either 6 or 3% glycerol and frozen in 0.5 ml straws. After thawing, the responses of all sperm parameters recorded were not significantly different between sub-optimal glycerol concentration (3%) and optimal glycerol concentration (6%) for untreated semen groups (0 mg CLC/100 Ã 106). Similarly, no significant differences were recorded between glycerol concentrations when semen samples were treated with 2 mg CLC/100 Ã 106 cells prior to cryopreservation. However, sperm treated with CLC prior to cryopreservation in diluents containing a sub-optimal concentration of glycerol (3%), recorded significantly higher (P < 0.05) percentages of total motile sperm, progressive motility, viability and acrosomal integrity, than for optimal glycerol concentrations (6%) for up to 4 h of in vitro incubation, at 38.5 °C after cryopreservation and thawing. Results suggest that in ram spermatozoa, a combination of 2 mg cholesterol-loaded cyclodextrins (CLC)/100 Ã 106 and a sub-optimal concentration of glycerol (3%) in a Tris-based diluent helps to reduce the acrosomal damage observed during cryopreservation, maintaining sperm viability and motility.
Journal: Small Ruminant Research - Volume 100, Issues 2â3, October 2011, Pages 164-168