title: Antioxidant supplementation in vitro improves boar sperm motility and mitochondrial membrane potential after cryopreservation of different fractions of the ejaculate.
abstract: Antioxidant supplementation during cooling was assayed to improve the motility of frozen-thawed (FT) boar spermatozoa from two different fractions of the ejaculate, the first component of the sperm-rich fraction (Fraction I) and the rest of the bulk ejaculate (Fraction II). Using a split-sample design, addition of two different concentrations (100 and 200 microMl(-1)) of the water-soluble Vitamin E analogue Trolox (6-hydroxy -2,5,7,8-tetramethylchroman -2-carboxylic acid) was evaluated for an effect on sperm motility (measured both subjectively and by means of a computer assisted motility assessment (CASA)), and on mitochondrial membrane potential using flow cytometry after cell-loading with JC-1. The effect of the Vitamin E analogue was clearly dose-dependent and varied with the fraction of the ejaculate considered. Motility was significantly higher in Trolox-treated spermatozoa (200 microm), from either ejaculate fraction, albeit the effect was more evident in spermatozoa from Fraction II (P<0.05) for any Trolox-concentration. Antioxidant supplementation resulted, also dose-dependent, in a higher number of spermatozoa showing high mitochondrial activity as assessed by the JC-1 staining, in both ejaculate fractions. In the present trial, exogenous Trolox positively affected post-thaw sperm viability (as motility and mitochondrial membrane potential) in both fractions of the ejaculate. The magnitude of the effect appeared, however, to be dependent of the fraction of the ejaculate considered.
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences (SLU), Box 7039, SE-750-07 Uppsala, Sweden. fjuanpvega@unex.es
authors.forename: F J
authors.initials: FJ
authors.lastname: Peña
authors.forename: A
authors.initials: A
authors.lastname: Johannisson
authors.forename: M
authors.initials: M
authors.lastname: Wallgren
authors.forename: H
authors.initials: H
authors.lastname: Rodriguez Martinez
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002839:Chromans / Q000008:administration & dosage / Q000494:pharmacology; D015925:Cryopreservation / Q000662:veterinary*; D004305:Dose-Response Relationship, Drug; D004542:Ejaculation; D008297:Male; D008928:Mitochondria / Q000187:drug effects; D012662:Semen Preservation / Q000662:veterinary*; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000648:ultrastructure; D013552:Swine
chemical_list: D000975:Antioxidants; D002839:Chromans; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid