1. Reactive oxygen and nitrogen species can damage biomolecules if these lack sufficient antioxidant protection. Maintaining and up-regulating antioxidant defenses and repair of the damaged molecules require resources that could potentially be allocated to other functions, including lifehistory and signal traits. 2. Identifying the physiological mechanisms causing and counteracting oxidative da...

Oxidative stress is implicated in the etiology of many diseases, including alcoholic liver disease (ALD). Peroxiredoxin 6 is a cytosolic peroxidase that has been demonstrated to protect various tissues, such as skin, lung, and cardiac muscle, against acute oxidative insults. Consequently, peroxiredoxin 6 was hypothesized to also protect the liver from oxidative stress generated during the proce...

The risk of oxidative stress-related metabolic diseases increases with menopause and physical inactivity. We hypothesized that an 8-week Tai Chi (TC) training program (2 sessions in class; 2 sessions at home; 1-1:15/session) would improve antioxidant capacity and reduce cardiovascular risks in both pre- (n = 8) and postmenopausal (n = 7) sedentary women. Selected measures of physical fitness an...

Legume root nodules are sites of intense biochemical activity and consequently are at high risk of damage as a result of the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). These molecules can potentially give rise to oxidative and nitrosative damage but, when their concentrations are tightly controlled by antioxidant enzymes and metabolites, they also play posi...

In order to facilitate the study of oxidative stress in lung tissue, rat lung slices with impaired antioxidant defenses were prepared and used. Incubation of lung slices with the antineoplastic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) (100 microM) in an amino acid-rich medium for 45 min produced a near-maximal (approximately 85%), irreversible inhibition of glutathione reductase, accom...

Akt, a protein kinase hyperactivated in many tumors, plays a major role in both cell survival and resistance to tumor therapy. A recent study,1 along with other evidences, shows interestingly, that Akt is not a single-function kinase, but may facilitate rather than inhibit cell death under certain conditions. This hitherto undetected function of Akt is accomplished by its ability to increase re...

Free radicals generated as byproducts of normal metabolism can damage biologically relevant molecules. When their generation is increased, damage can also be increased, resulting in the development of many pathological conditions. Antioxidant defenses protect the body from the detrimental effects of free radicals. Dietary fruits and vegetables provide a reasonable amount of compounds that act a...

Cells devoid of cytosolic superoxide dismutase (SOD) suffer enzyme inactivation, growth deficiencies, and DNA damage. It has been proposed that the scant superoxide (O2-) generated by aerobic metabolism harms even cells that contain abundant SOD. However, this idea has been difficult to test. To determine the amount of O2- that is needed to cause these defects, we modulated the O2- concentratio...

The aim was to study the effects of a scuba diving session on the lymphocyte antioxidant system, NO synthesis, the capability to produce reactive oxygen species and the antioxidant response in neutrophils. For that purpose seven male divers performed an immersion at a depth of 40 m for 25 min. The same parameters were measured after an hyperbaric oxygen (HBO) treatment at resting conditions in ...

Reactive oxygen species (ROS) formation is part of normal cellular aerobic metabolism, due to respiration and oxidation of nutrients in order to generate energy. Low levels of ROS are involved in cellular signaling and are well controlled by the cellular antioxidant defense system. Elevated levels of ROS generation due to pollutants, toxins and radiation exposure, as well as infections, are ass...