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Antioxidant enzyme activity and oxidative stress in bovine oocyte in vitro maturation.
IUBMB Life. 2001 Jan; 51(1):57-64.IL

Abstract

Reactive oxygen species (ROS) production is a normal process of cell metabolism. In vitro environments usually increase cell production of ROS, which has been implicated as a main cause of cell damage. Nevertheless, the role of ROS in oocyte in vitro maturation (IVM) is controversial. In most cells, enzymatic antioxidant systems can attenuate the effect of oxidative stress by scavenging ROS. The aim of this work was to determine whether: (1) standard conditions of bovine oocyte IVM are responsible for oxidative stress; (2) cumulus cells participate in protection against oxidative stress of the oocyte; and (3) enzymatic antioxidant activity is present in oocytes and cumulus cells. Cumulus-oocyte complexes (COCs) were matured in TCM-199 + 10% steer serum for 24 h at 39 degrees C in 5% CO2:95% humidified air. Oxidative stress was determined by the 2',7'-dichlorofluorescein diacetate assay. Superoxide dismutase (SOD), glutathione peroxidase, and catalase activities were measured spectrophotometrically. Under standard conditions of in vitro maturation, there was no increase in ROS production per COC (P > 0.05), but ROS level per cumulus cell diminished. There was no modification in ROS levels in oocytes matured in the presence versus the absence of their surrounding cumulus cells (P > 0.05). To the best of our knowledge, the presence of SOD, glutathione peroxidase and catalase activities were detected in oocytes and cumulus cells for the first time. Enzymatic units were lower in denuded oocytes with respect to cumulus (P < 0.05), accounting for 37% for SOD, 25% for glutathione peroxidase, and 11% for catalase of the total COC units. Specific enzyme activity diminished in cumulus cells (P > 0.05) and increased in oocytes due to maturation (P > 0.05). The presence of activity of an enzymatic antioxidant system in the bovine oocyte would regulate in part ROS levels during IVM. Oocytes could be capable of controlling the increase in ROS because of the presence of their own enzymatic antioxidant system, SOD having the highest specific activity with respect to cumulus cells.

Authors+Show Affiliations

Area of Biochemistry, School of Veterinary Sciences, University of Buenos Aires, Argentina.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

11419698

Citation

Cetica, P D., et al. "Antioxidant Enzyme Activity and Oxidative Stress in Bovine Oocyte in Vitro Maturation." IUBMB Life, vol. 51, no. 1, 2001, pp. 57-64.
Cetica PD, Pintos LN, Dalvit GC, et al. Antioxidant enzyme activity and oxidative stress in bovine oocyte in vitro maturation. IUBMB Life. 2001;51(1):57-64.
Cetica, P. D., Pintos, L. N., Dalvit, G. C., & Beconi, M. T. (2001). Antioxidant enzyme activity and oxidative stress in bovine oocyte in vitro maturation. IUBMB Life, 51(1), 57-64.
Cetica PD, et al. Antioxidant Enzyme Activity and Oxidative Stress in Bovine Oocyte in Vitro Maturation. IUBMB Life. 2001;51(1):57-64. PubMed PMID: 11419698.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Antioxidant enzyme activity and oxidative stress in bovine oocyte in vitro maturation. AU - Cetica,P D, AU - Pintos,L N, AU - Dalvit,G C, AU - Beconi,M T, PY - 2001/6/23/pubmed PY - 2002/1/5/medline PY - 2001/6/23/entrez SP - 57 EP - 64 JF - IUBMB life JO - IUBMB Life VL - 51 IS - 1 N2 - Reactive oxygen species (ROS) production is a normal process of cell metabolism. In vitro environments usually increase cell production of ROS, which has been implicated as a main cause of cell damage. Nevertheless, the role of ROS in oocyte in vitro maturation (IVM) is controversial. In most cells, enzymatic antioxidant systems can attenuate the effect of oxidative stress by scavenging ROS. The aim of this work was to determine whether: (1) standard conditions of bovine oocyte IVM are responsible for oxidative stress; (2) cumulus cells participate in protection against oxidative stress of the oocyte; and (3) enzymatic antioxidant activity is present in oocytes and cumulus cells. Cumulus-oocyte complexes (COCs) were matured in TCM-199 + 10% steer serum for 24 h at 39 degrees C in 5% CO2:95% humidified air. Oxidative stress was determined by the 2',7'-dichlorofluorescein diacetate assay. Superoxide dismutase (SOD), glutathione peroxidase, and catalase activities were measured spectrophotometrically. Under standard conditions of in vitro maturation, there was no increase in ROS production per COC (P > 0.05), but ROS level per cumulus cell diminished. There was no modification in ROS levels in oocytes matured in the presence versus the absence of their surrounding cumulus cells (P > 0.05). To the best of our knowledge, the presence of SOD, glutathione peroxidase and catalase activities were detected in oocytes and cumulus cells for the first time. Enzymatic units were lower in denuded oocytes with respect to cumulus (P < 0.05), accounting for 37% for SOD, 25% for glutathione peroxidase, and 11% for catalase of the total COC units. Specific enzyme activity diminished in cumulus cells (P > 0.05) and increased in oocytes due to maturation (P > 0.05). The presence of activity of an enzymatic antioxidant system in the bovine oocyte would regulate in part ROS levels during IVM. Oocytes could be capable of controlling the increase in ROS because of the presence of their own enzymatic antioxidant system, SOD having the highest specific activity with respect to cumulus cells. SN - 1521-6543 UR - https://www.unboundmedicine.com/medline/citation/11419698/Antioxidant_enzyme_activity_and_oxidative_stress_in_bovine_oocyte_in_vitro_maturation_ L2 - https://doi.org/10.1080/15216540119253 DB - PRIME DP - Unbound Medicine ER -