The objective of this study was to evaluate efficiency of methyl-beta-cyclodextrin (MBCD) in the sperm preservation of bull. For this study, the freezing of diluted semen were added with Triladyl containing 20% egg-yolk and/or 0, 1, 5, 10 and 20 mM MBCD before freezing process. Analysis of viability in frozen-thawed sperm was estimated by SYBR14/PI double stain, hypoosmotic swelling test(HOST) and acrosome damage with FITC-PNA, and mitochondria activation with Rhodamin123 by flow-cytometry. The sperm viability was significantly higher in 0 mM and 5 mM concentrations of MBCD than other groups (p<0.05). However, the HOST was significantly lower at 20 mM concentration of MBCD than other concentrations (p<0.05). In addition, acrosome damage and mitochondria activation rates were significantly lower at 20 mM concentration of MBCD than other groups (p<0.05). In conclusion, the viability of sperm was not significantly different among concentrations of MBCD 0, 5 and 10 mM, but MBCD 20 mM was significantly lower than other groups. In addition, as concentrations of MBCD was high, HOST, acrosome damage and mitochondria activation rates had a negative effect in bull sperm.

This study was undertaken to find out the effect of methyl-beta-cyclodextrin (MBCD) on cold shock and membrane cholesterol quantity of sperm during the freezing process in miniature pigs. For this study, semen ejaculated from PWG M-type miniature pig was diluted that freezing solution (with egg yolk group) and m-Modena B (without egg yolk group) treated with 0, 1, 5, 10 and 20 mM MBCD before freezing process. The diluted semen was monitored sperm ability at room temperature, after cooled until 5℃ and after forzen-thawed for cold shock test of spermatozoa. Also, membrane cholesterol of sperm was extracted by folch solution at the same time. sperm ability was assessed for viability and acrosomal status. The membrane cholesterol quantity was measured by thin-layer chromatography (TLC) method. The result, viability and acrosome integrity in semen diluted without egg yolk groups were decreased at all temperature range by increasing of MBCD concentration. In particular, sperm of egg yolk group was showed that significantly higher viability and lower acrosome damage when treated with 5 mM MBCD (p<0.05). The results of TLC experiment, cholesterol amounts were increased with MBCD cocentration in egg yolk, and decreased with MBCD concentration in m-Modena B. In cryopreservation efficiency, there was no significant difference at viability, and acrosomal state of sperm in 5 mM MBCD concentration was significantly lower in acrosome damage than other groups (p<0.05). Therefore, the addition MBCD in egg yolk was protected spermatozoa from cold shock injury. This protective effect of MBCD may be due to addition of sperm membrane cholesterol.

정자의 수정능력획득과 첨체반응은 Ca에 의존적으로 일어나며, 수정능력획득 과정에서는 원형질막으로부터 cholesterol이 방출되어 첨체반응이 일어나기 쉬운 상태로 전환된다. 최근 세포막으로부터 cholesterol 방출을 촉진하는 methyl beta cyclodextrin (MBCD)이 첨체반응을 유발함이 알려졌으나 정자 주변의 Ca 농도와 관계없이 cholesterol 방출만으로 첨체반응이 유발되는지의 여부는 확인되지 않았다. 본 연구에서는 생쥐