Dual role of oxygen during lipoxygenase reactions

Dual role of oxygen during lipoxygenase reactions.

Studying the oxygenation kinetics of (19R/S,5Z,8Z,11Z,14Z)-19-hydroxyeicosa-5,8,11,14-tetraenoic acid (19-OH-AA) by rabbit 15-lipoxygenase-1 we observed a pronounced oxygen dependence of the reaction rate, which was not apparent with arachidonic acid as substrate. Moreover, we found that peroxide-dependent activation of the lipoxygenase depended strongly on the oxygen concentration. These data ...

Dual role of reactive oxygen species in vascular growth.

In the last decade, it has become clear that virtually all mammalian cells produce reactive oxygen species. It was generally believed that these were by-products of cellular respiration and metabolism, and that they exerted toxic effects, including DNA damage and lipid oxidation. Recent evidence has demonstrated that this concept is incorrect, and that reactive oxygen species are produced in a ...

Water-Assisted Oxygen Activation During Selective Oxidation Reactions

Tumorogensis : The Dual Role of Telomerase

  Carcinogenesis is a multistep process characterized by the gradual accumulation of genetic changes that ultimately lead to cancer. These genetic mutations can impart limitless replicative potential to the cancer cells making them immortal. Telomeres are repeat nucleotide sequence TTAGGG that are present at the end of chromosomes. Its functions are to protect the chromosomal ends and to ensur...

Evaluation of adherence to oxygen therapy standards before, during and after oxygen hood administration

Background and Purpose: Oxygen therapy is one of the common treatments for neonates with cardiopulmonary disease. The aim of this study was to evaluate adherence to oxygen therapy standards by nurses before, during and after using oxygen hood. Methods: In this cross-sectional study, 250 cases of nursing care were evaluated before, during and after administration of oxygen hood therapy in pre...