Purinergic receptors, also known as purinoceptors, are a family of plasma membrane molecules found in many mammalian tissues. Purinergic receptors are transmembrane receptors consisting of two main categories. P1 receptors are stimulated by adenosine. Those that respond to extracellular nucleotides (ATP, ADP, UTP and UDP) are P2 receptors. The P2X receptors are ligand-gated ion channels. The P1 and P2Y receptors are bound to the G protein. Both of these metabotropic receptors are distinguished by taking into account their reactivity to specific activators. P1 and P2Y receptors are widely distributed in the brain, heart, kidneys and adipose tissue.
Part of the book: Receptors P1 and P2 as Targets for Drug Therapy in Humans
The aim of this study is to give information to readers about the importance of glutathione peroxidase. The physiopathology of most diseases is not fully elucidated currently; however, in many epidemiological studies, there are limited studies indicating the relationship between low levels of glutathione peroxidase status and the rise of cancer risk in many types of cancer. Anytime, situations in case of the distortion due to imbalance between enzymatic and nonenzymatic antioxidants and oxidants which lost one of paired electrons in the atomic level mean reactive oxygen species (ROS) withal reactive nitrogen species (RNS) in favor of oxidants that are related to oxidative stress. The possible mechanisms of glutathione peroxidase have been reviewed using the major findings of more than 1000 papers related to the ROS, glutathione peroxidase, and oxidative stress. Oxidative stress plays an important role in the occurrence and development of most diseases in both animal and human studies. Moreover, antioxidants have protective effects against nearly 50 disease pathogenesis. Oxidative stress, which occurs as an outcome of lipid peroxidation, concurrently may have a key importance in the phase of carcinogenesis occurring with a multistage course devoted to environmental toxicity and in cancer pathogenesis.
Part of the book: Glutathione System and Oxidative Stress in Health and Disease