title: Pentoxifylline effects on capacitation and fertility of stallion epididymal sperm.
abstract: The aims of this study were to determinate whether pentoxifylline (PTX) increases the motion parameters of fresh and frozen-thawed equine epididymal spermatozoa, to evaluate the tyrosine phosphorylation of frozen-thawed epididymal sperm in the presence of PTX and to determine whether the PTX-treatment of stallion epididymal sperm prior to freezing improves the fertility response of mares to a reduced number of spermatozoa per insemination dose. Fifty epididymis were flushed with a skim milk based extender with or without PTX. The pre-treatment with PTX enhanced the sperm motility after being harvested (P<0.05); however the freeze-thaw process did not alter the sperm kinematics between control and treated samples (P>0.05). Plasma membrane integrity did not differ between control and PTX group after recovery and after thawing (P>0.05), as observed in tyrosine phosphorylation, which the PTX treatment did not alter the percentage of tail-associated immunofluorescence of cryopreserved epididymal sperm (P>0.05). For the fertility trial, different insemination groups were tested: 800×106epididymal sperm (C800); 100×106epididymal sperm (C100); 100×106epididymal sperm recovered in an extender containing PTX (PTX100). The conception rates for C800; C100 and PTX100 were 68.7% (11/16); 31.5% (5/16) and 50% (8/16), respectively. The conception rate did not differ among groups (P>0.05), however, a low number of animals was used in this study. A trend toward significance (P=0.07) was observed between C800 and C100 groups. In conclusion, PTX has no deleterious effect on sperm motility, viability and capacitation of cryopreserved stallion epididymal sperm. The conventional artificial insemination with 100×106sperm recovered with PTX ensures acceptable conception rates and maximize the limited number of doses of cryopreserved stallion epididymal sperm.
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, Brazil. Electronic address: priguasti@gmail.com.
authors.forename: P N
authors.initials: PN
authors.lastname: Guasti
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, Brazil.
authors.forename: G A
authors.initials: GA
authors.lastname: Monteiro
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, Brazil.
authors.forename: R R D
authors.initials: RR
authors.lastname: Maziero
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, Brazil.
authors.forename: M T
authors.initials: MT
authors.lastname: Carmo
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, Brazil.
authors.forename: J A
authors.initials: JA
authors.lastname: Dell'Aqua
authors.affiliation: Santo Amaro University, São Paulo, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Crespilho
authors.affiliation: Division of Molecular & Computational Toxicology, Vrije Universiteit Amsterdam, The Netherlands.
authors.forename: E A
authors.initials: EA
authors.lastname: Rifai
authors.affiliation: Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, Brazil.
authors.forename: F O
authors.initials: FO
authors.lastname: Papa
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000662:veterinary; D004822:Epididymis / Q000166:cytology*; D005260:Female; D005298:Fertility / Q000187:drug effects; D006736:Horses / Q000502:physiology*; D008297:Male; D010431:Pentoxifylline / Q000494:pharmacology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010766:Phosphorylation; D011247:Pregnancy; D012662:Semen Preservation / Q000662:veterinary; D013075:Sperm Capacitation / Q000187:drug effects*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects*; D014443:Tyrosine / Q000502:physiology
chemical_list: D010726:Phosphodiesterase Inhibitors; D014443:Tyrosine; D010431:Pentoxifylline
keywords: Cauda epididymal sperm; Epididymis; Flushing extender; Insemination dose; Tyrosine phosphorylation