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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Effects of melatonin on production of reactive oxygen species and developmental competence of bovine oocytes exposed to heat shock and oxidative stress during in vitro maturation

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Author(s):
Cavallari, Fernanda de Castro [1, 2, 3] ; Verde Leal, Claudia Lima [1] ; Zvi, Roth [4] ; Hansen, Peter J. [2, 3]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Fac Anim Sci & Food Engn, Dept Vet Med, BR-13635900 Pirassununga - Brazil
[2] Univ Florida, DH Barron Reprod & Perinatal Biol Res Program, Dept Anim Sci, Gainesville, FL 32611 - USA
[3] Univ Florida, Genet Inst, Gainesville, FL 32611 - USA
[4] Hebrew Univ Jerusalem, Robert H Smith Fac Agr Food & Environm, Dept Anim Sci, IL-76100 Rehovot - Israel
Total Affiliations: 4
Document type: Journal article
Source: ZYGOTE; v. 27, n. 3, p. 180-186, JUN 2019.
Web of Science Citations: 2
Abstract

Heat shock may disrupt oocyte function by increasing the generation of reactive oxygen species (ROS). We evaluated the capacity of the antioxidant melatonin to protect oocytes using two models of oxidative stress - heat shock and the pro-oxidant menadione. Bovine cumulus-oocyte complexes (COC) were exposed in the presence or absence of 1 mu M melatonin to the following treatments during maturation: 38.5 degrees C, 41 degrees C and 38.5 degrees C+5 mu M menadione. In the first experiment, COC were matured for 3 h with 5 mu M CellROX (R) and analyzed by epifluorescence microscopy to quantify production of ROS. The intensity of ROS was greater for oocytes exposed to heat shock and menadione than for control oocytes. Melatonin reduced ROS intensity for heat-shocked oocytes and oocytes exposed to menadione, but not for control oocytes. In the second experiment, COC were matured for 22 h. After maturation, oocytes were fertilized and the embryos cultured for 7.5 days. The proportion of oocytes that cleaved after fertilization was lower for oocytes exposed to heat shock and menadione than for control oocytes. Melatonin increased cleavage for heat-shocked oocytes and oocytes exposed to menadione, but not for control oocytes. Melatonin tended to increase the developmental competence of embryos from heat-shocked oocytes but not for embryos from oocytes exposed to menadione or from control oocytes. In conclusion, melatonin reduced production of ROS of maturing oocytes and protected oocytes from deleterious effects of both stresses on competence of the oocyte to cleave after coincubation with sperm. These results suggest that excessive production of ROS compromises oocyte function. (AU)

FAPESP's process: 17/04376-6 - Functional study of the melatonin receptor MT1 in bovine cumulus-oocyte complexes and its importance on oocyte maturation and embryo development in vitro under normal and heat stress culture conditions
Grantee:Fernanda Cavallari de Castro
Support type: Scholarships abroad - Research Internship - Doctorate
FAPESP's process: 15/20379-0 - Studies regarding melatonin on the function and quality of bovine cumulus-oocyte complexes
Grantee:Cláudia Lima Verde Leal
Support type: Regular Research Grants