title: Heat stress and antioxidant enzyme activity in bubaline (Bubalus bubalis) oocytes during in vitro maturation.
abstract: In vitro environments like heat stress usually increase the production of reactive oxygen species in bubaline oocytes which have been implicated as one of the major causes for reduced developmental competence. Oocytes during meiotic maturation are sensitive to oxidative stress, and heat stress accelerates cellular metabolism, resulting in the higher production of free radicals. Therefore, the aim of present work was to assess the impact of heat stress during meiotic maturation on bubaline cumulus-oocyte complexes (COC), denuded oocytes (DO), and cumulus cell mass in terms of their oxidative status. Accordingly, for control group, COC were matured at 38.5 °C for complete 24 h of meiotic maturation and heat stress of 40.5 and 41.5 °C was applied to COC during the first 12 h of maturation and then moved to 38.5 °C for rest of the 12 h. In another group, COC after maturation were denuded from the surrounding cumulus cells by manual pipetting. Results indicated that the production of reactive oxygen species (ROS), lipid peroxides, and nitric oxide (NO) was significantly (P < 0.05) higher in the oocytes subjected to heat stress (40.5 and 41.5 °C) during meiotic maturation compared to the oocytes matured under standard in vitro culture conditions (38.5 °C). Also, the antioxidant enzymatic activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase were significantly (P < 0.05) increased in all the treatment groups compared to the control group. Therefore, the present study clearly establishes that heat stress ensues oxidative stress in bubaline oocytes which triggers the induction of antioxidant enzymatic defense system for scavenging the ROS.
authors.affiliation: Division of Dairy Cattle Physiology, National Dairy Research Institute, Karnal, 132 001, Haryana, India. symaashraf@yahoo.co.in.
authors.forename: Syma Ashraf
authors.initials: SA
authors.lastname: Waiz
authors.affiliation: Animal Biochemistry Division, National Dairy Research Institute, Karnal, 132 001, Haryana, India.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Raies-Ul-Haq
authors.affiliation: Department of Biochemistry, Kurukshetra University, Kurukshetra, 136 119, Haryana, India.
authors.forename: Suman
authors.initials: S
authors.lastname: Dhanda
authors.affiliation: Division of Dairy Cattle Physiology, National Dairy Research Institute, Karnal, 132 001, Haryana, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Division of Dairy Cattle Physiology, National Dairy Research Institute, Karnal, 132 001, Haryana, India.
authors.forename: T Sridhar
authors.initials: TS
authors.lastname: Goud
authors.affiliation: Animal Biotechnology Center, National Dairy Research Institute, Karnal, 132 001, Haryana, India.
authors.forename: M S
authors.initials: MS
authors.lastname: Chauhan
authors.affiliation: Division of Dairy Cattle Physiology, National Dairy Research Institute, Karnal, 132 001, Haryana, India.
authors.forename: R C
authors.initials: RC
authors.lastname: Upadhyay
mesh_terms: D000818:Animals; D002020:Buffaloes; D002374:Catalase / Q000378:metabolism; D048708:Cell Growth Processes; D005260:Female; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006358:Hot Temperature / Q000009:adverse effects*; D008054:Lipid Peroxides / Q000378:metabolism; D008540:Meiosis; D009569:Nitric Oxide / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D008054:Lipid Peroxides; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione
keywords: Bubaline; Heat stress; In vitro maturation; Oocyte; Oxidative stress; ROS