Effect of cholesterol or cholesteryl conjugates on the cryosurvival of bull sperm

摘要: Different cholesterol conjugates-loaded-cyclodextrin was added to bull sperm improve quality after freezing. Ejaculates from four bulls were diluted 120 million cells/ml in Tris (T) diluent and then sub-divided into 10 treatments as follow: no additive (control); 1.5mg CLC (positive control); 0.75 mg or of cyclodextrin pre-loaded with conjugated heptanoate, palmitate, pelargonate stearate, incubated for 15 min at 22 degrees C. The samples 1:1 20% egg yolk (EY) T cooled 5 C over a 2h. Upon reaching C, the containing 10% EY+16% glycerol, allowed equilibrate min, packaged 0.5 ml straws frozen static liquid nitrogen vapor 20 before being plunged storage. Straws thawed motility, viability number binding perivitelline membrane determined. ability bind oocyte membranes conducted using chicken (CEPM) described by Barbato et al. [G.F. Barbato, P.G. Cramer, R.H. Hammerstedt, A practical vitro sperm-egg assay that detects subfertile males. Biol. Reprod. 58 (1998) 686-699] modified Amorim [E. Amorim, J.K. Graham, B. Spizziri, M. Meyers, L. Torres, effect adding cholesteryl-heptanoate, -palmitate, -pelargonate, -stearate loaded on cryosurvival, in: Proceeding 40th Annual Meeting Society Study Reproduction (SSR), July, San Antonio, TX, EUA, 2007], where these authors did not observe difference between bovine zona pellucide CEPM. Higher percentages motile viable maintained thawing treated compared all other (P 0.05). percentage higher control (P<0.05). Therefore, either improved cell whereas cyclodextrins cholesterol-like molecules not.