title: Activation of cyclooxygenases by H2O2 and t-butylhydroperoxide in aged rat lung.
abstract: The arachidonate cascade is important for the generation of reactive species (RS), and cyclooxygenase (COX) is a key enzyme of this cascade. Tissues of 24-month-old rat lung showed a 2-fold increase in RS, malondialdehyde and thromboxane B2 than those of 6-month-old rat. We found that the effects of 50 microM H2O2 and 200 microM t-butylhydroperoxide (t-BHP) specify on COX activity, and that their effects increased cytosolic COX activity in a concentration-dependent manner (1-50 microM) in 24-month-old rat. Our results suggested that COX activators such as t-BHP and H2O2, which are located in cytosol, are essential for the activation of COX in aged lung.
authors.affiliation: Department of Pharmacy, Pusan National University, Busan, Korea.
authors.forename: Jee Won
authors.initials: JW
authors.lastname: Im
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: Kim
authors.forename: Nam Deuk
authors.initials: ND
authors.lastname: Kim
authors.forename: Jae Sue
authors.initials: JS
authors.lastname: Choi
authors.forename: Byung Pal
authors.initials: BP
authors.lastname: Yu
authors.forename: Hee-Sun
authors.initials: HS
authors.lastname: Yang
authors.forename: Hae Young
authors.initials: HY
authors.lastname: Chung
mesh_terms: D000375:Aging / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008168:Lung / Q000187:drug effects* / Q000201:enzymology*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D011451:Prostaglandin-Endoperoxide Synthases / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D017382:Reactive Oxygen Species / Q000819:agonists / Q000378:metabolism*; D020122:tert-Butylhydroperoxide / Q000494:pharmacology*
chemical_list: D017382:Reactive Oxygen Species; D020122:tert-Butylhydroperoxide; D006861:Hydrogen Peroxide; D011451:Prostaglandin-Endoperoxide Synthases