title: Dose-dependent effect of melatonin on postwarming development of vitrified ovine embryos.
abstract: After cryopreservation, embryos become sensitive to the oxidative stress, resulting in lipid peroxidation, membrane injury, and structural destruction. The present study aimed to assess the effect of increasing concentration of melatonin during postwarming culture on embryo's ability to restore its functions after cryopreservation. In vitro-produced blastocysts were vitrified, warmed, and cultured in vitro in TCM 199 with 5 different supplementations: control (CTR): 10% fetal calf serum; bovine serum albumin (BSA): 0.04% (wt/vol) BSA; and MEL(-3), MEL(-6), MEL(-9): BSA plus melatonin 10(-3), 10(-6), and 10(-9) M. The medium with the highest melatonin concentration had the highest trolox equivalent antioxidant capacity, whose values were comparable with those determined in plasma sampled from adult ewes (8.7 ± 2.4 mM). The other media had lower trolox equivalent antioxidant capacity values (P < 0.01), below the range of the plasma. At the same time, embryos cultured with the highest melatonin concentration reported a lower in vitro viability, as evaluated by lower re-expansion and hatching rates, and lower total cell number compared with the other groups (P < 0.05). Their metabolic status was also affected, as evidenced by higher oxidative and apoptotic index and lower ATP concentration. The beneficial effects of melatonin on embryo development during postwarming culture were observed only at low concentration (10(-9) M). These results suggest that melatonin at high concentration may exert some degree of toxic activity on pre-implantation embryos. Thus, the dose at which the embryos are exposed is pivotal to obtain the desiderate effect.
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Succu
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Pasciu
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Manca
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Chelucci
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Torres-Rovira
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Giovanni G
authors.initials: GG
authors.lastname: Leoni
authors.affiliation: Department of Biomedical Science, University of Sassari, Sassari, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Zinellu
authors.affiliation: Department of Biomedical Science, University of Sassari, Sassari, Italy.
authors.forename: Ciriaco
authors.initials: C
authors.lastname: Carru
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Naitana
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Sassari, Italy. Electronic address: berling@uniss.it.
authors.forename: Fiammetta
authors.initials: F
authors.lastname: Berlinguer
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D000975:Antioxidants; D001755:Blastocyst / Q000502:physiology; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003470:Culture Media; D053938:DNA Fragmentation; D004305:Dose-Response Relationship, Drug; D046149:Embryo Culture Techniques / Q000379:methods / Q000662:veterinary; D047108:Embryonic Development / Q000187:drug effects*; D005307:Fertilization in Vitro / Q000662:veterinary; D006358:Hot Temperature; D008550:Melatonin / Q000008:administration & dosage* / Q000009:adverse effects; D017382:Reactive Oxygen Species / Q000032:analysis; D034561:Sheep, Domestic / Q000196:embryology*
chemical_list: D000975:Antioxidants; D003470:Culture Media; D017382:Reactive Oxygen Species; D000255:Adenosine Triphosphate; D008550:Melatonin
keywords: ATP; Apoptosis; In vitro embryo production; Oxidative stress; Total antioxidant capacity