title: Effect of extracellular adenosine 5'-triphosphate on cryopreserved epididymal cat sperm intracellular ATP concentration, sperm quality, and in vitro fertilizing ability.
abstract: Intracellular adenosine 5'-triphosphate (ATP) is essential for supporting sperm function in the fertilization process. During cryopreservation, damage of sperm mitochondrial membrane usually leads to compromised production of intracellular ATP. Recently, extracellular ATP (ATPe) was introduced as a potent activator of sperm motility and fertilizing ability. This study aimed to evaluate (1) levels of intracellular ATP in frozen-thawed epididymal cat sperm after incubation with ATPe and (2) effects of ATPe on epididymal cat sperm parameters after freezing and thawing. Eighteen male cats were included. For each replicate, epididymal sperm from two cats were pooled to one sample (N = 9). Each pooled sample was cryopreserved with the Tris-egg yolk extender into three straws. After thawing, the first and second straws were incubated with 0-, 1.0-, or 2.5-mM ATPe for 10 minutes and evaluated for sperm quality at 10 minutes, 1, 3, and 6 hours after thawing and fertilizing ability. The third straw was evaluated for intracellular ATP concentration in control and with 2.5-mM ATPe treatment. Higher concentration of intracellular sperm ATP was observed in the samples treated with 2.5-mM ATPe compared to the controls (0.339 ± 0.06 μg/2 × 10(6) sperm vs. 0.002 ± 0.003 μg/2 × 10(6) sperm, P ≤ 0.05). In addition, incubation with 2.5-mM ATPe for 10 minutes promoted sperm motility (56.7 ± 5.0 vs. 53.3 ± 4.4%, P ≤ 0.05) and progressive motility (3.1 ± 0.2 vs. 2.8 ± 0.4, P ≤ 0.05), mitochondrial membrane potential (36.4 ± 5.5 vs. 28.7 ± 4.8%, P ≤ 0.05), and blastocyst rate (36.1 ± 7.0 and 28.8 ± 7.4%, P ≤ 0.05) compared with the controls. In contrast, ATPe remarkably interfered acrosome integrity after 6 hours of postthawed incubation. In sum, the present finding that optimal incubation time of postthaw epididymal cat sperm under proper ATPe condition might constitute a rationale for the studies on other endangered wild felids regarding sperm quality and embryo development.
authors.affiliation: Department of Obstetrics, Gynaecology and Reproduction, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand; Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, Washington DC, USA.
authors.forename: Paweena
authors.initials: P
authors.lastname: Thuwanut
authors.affiliation: Department of Preclinic and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand.
authors.forename: Nlin
authors.initials: N
authors.lastname: Arya
authors.affiliation: Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, Washington DC, USA.
authors.forename: Pierre
authors.initials: P
authors.lastname: Comizzoli
authors.affiliation: Department of Obstetrics, Gynaecology and Reproduction, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand. Electronic address: ckaywale@yahoo.com.
authors.forename: Kaywalee
authors.initials: K
authors.lastname: Chatdarong
mesh_terms: D000177:Acrosome / Q000187:drug effects; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D002415:Cats; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary; D008297:Male; D053078:Membrane Potential, Mitochondrial; D055101:Semen Analysis / Q000662:veterinary; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility; D053625:Sperm Retrieval / Q000662:veterinary; D013094:Spermatozoa / Q000187:drug effects*
chemical_list: D000255:Adenosine Triphosphate
keywords: Energy; Felid; Sperm freezing; Sperm function