Polyamines protect against radiation-induced oxidative stress.
Astronauts and cosmonauts are exposed to a wide variety of different hazards while in space that include radiation, which presents one of the most critical barriers to long-term missions. A major deleterious effect directly associated with ionizing radiation is the production of reactive oxygen species (ROS) such as peroxides and hydroxyl radicals. The free radicals generated by ultraviolet (UV) or ionizing radiation can attack cellular lipids, proteins and DNA. Endogenous free radical scavengers such as glutathione and the polyamines (e.g, spermidine and spermine) can inhibit the action of ROS. In particular, heme oxygenase-1 (HO-1), the enzyme involved in heme protein metabolism, can provide antioxidant protection through the production of the antioxidant bilirubin. Furthermore, polyamines have been shown to indirectly increase HO-1 content and antioxidant protection. The beta2-adrenoceptor agonist clenbuterol has been shown to stimulate polyamine synthesis and by extension, might provide a margin of antioxidant protection through increasing HO-1 content. However, it is unclear whether the polyamines are acting as a tertiary messengers for antioxidant protection in the be beta2-adrenoceptor signal transduction pathway. The purpose of this study was to study the role of the polyamine pathway in attenuating free radical-induced damage.
von Deutsch
Albert W
AW
Space Medicine and Life Sciences Research Center, USA.
Mitchell
Clarence D
CD
Williams
Chris E
CE
Dutt
Kamla
K
Silvestrov
Natalia A
NA
Klement
Brenda J
BJ
Abukhalaf
Imad K
IK
von Deutsch
Daniel A
DA
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects; D002976:Clenbuterol / Q000494:pharmacology; D003470:Culture Media / Q000528:radiation effects*; D000518:Eflornithine / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016166:Free Radical Scavengers; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D051547:Heme Oxygenase-1; D006801:Humans; D008565:Membrane Proteins; D009955:Ornithine Decarboxylase / Q000378:metabolism* / Q000528:radiation effects*; D018384:Oxidative Stress; D011073:Polyamines / Q000378:metabolism* / Q000528:radiation effects*; D011412:Propanolamines / Q000494:pharmacology; D017382:Reactive Oxygen Species; D012160:Retina / Q000166:cytology; D013482:Superoxide Dismutase / Q000494:pharmacology; D014466:Ultraviolet Rays
D000318:Adrenergic beta-Agonists; D003470:Culture Media; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D008565:Membrane Proteins; D011073:Polyamines; D011412:Propanolamines; D017382:Reactive Oxygen Species; C026777:ICI 118551; D002374:Catalase; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D013482:Superoxide Dismutase; D009955:Ornithine Decarboxylase; D002976:Clenbuterol; D000518:Eflornithine