Pre-exercise antioxidant enzyme activities determine the antioxidant enzyme erythrocyte response to exercise

Free radical production increases during exercise and oxidative damage occurs in several tissues. We examined the effects of three different exercise tests on the pattern of change of erythrocyte enzyme antioxidant activities. The tests were a short maximal exercise test, a submaximal prolonged exercise test and a cycling stage during competition. The participants were amateur and professional cyclists with different training statuses and different basal erythrocyte antioxidant enzyme activities. The maximal test produced no changes in the erythrocyte antioxidant enzyme activities of amateur sportsmen. The submaximal test, performed at 80% of maximal oxygen uptake, decreased erythrocyte catalase (12%), glutathione peroxidase determined with H₂O₂ (14%) and glutathione reductase (16%); superoxide dismutase activity increased by about 25%. The cycling stage performed by professional cyclists increased erythrocyte catalase (29%) and glutathione reductase (10%) activities. The in vivo changes in glutathione reductase activity were confirmed by in vitro measurements: hydrogen peroxide decreased and the presence of catalase increased the activity of this enzyme. In conclusion, we suggest that the different erythrocyte antioxidant enzyme responses to diverse exercise tests can be explained by the effects of hydrogen peroxide and the superoxide anion on the antioxidant enzyme activities in erythrocytes.     

Up in the air: Are airlines following the new DOT rules on equal pricing for people with disabilities when websites are inaccessible?

This paper details the findings from a study of airline compliance with Department of Transportation (DOT) regulations requiring that persons with disabilities not be discriminated against in the pricing of airline travel. These regulations mandate that if an airline website is inaccessible for persons with disabilities, the airline must charge the same price that is available on the website and may not charge a fee for purchasing tickets over the phone. To evaluate compliance, the websites of leading airlines were examined for accessibility in terms of the ability to check flight schedules and order tickets. Among the four airlines with barriers to accessibility on their websites, a series of phone calls were made by researchers to assess whether the DOT regulations would be followed. Two of the airlines, USAirways and United, practiced discriminatory pricing, even after being made aware of the regulations, in over one-third of the phone calls. This paper details the findings from the study and analyzes the data in terms of website accessibility, civil rights for travelers with disabilities, and policy implications.