Acceleration of tissue aging in chickens caused by oxidative stress using allopurinol and detected by cellular humoral chemiluminesence

The maximum longevity in birds is known to range from 4 years for blue jays (Cyanocitta cristata) to 64 years for macaws (Ara macao). The longevity of birds is somewhat surprising, since they exhibit many traits that should render them more susceptible to the degenerative processes of aging. These traits have been reviewed 2 and include (1) metabolic rates as much as 2 to 2.5 times greater than those of mammals of similar body size, (2) blood sugar levels typically two to six times higher than those of mammals, and (3) body temperatures about 3 ° C higher than mammals. Each of these factors should expose them to a higher rate of free oxygen radical production and accelerate the formation of Maillard products (Figure 29.1). Without special protective mechanisms against the potential for oxidative damage, birds should be comparatively short lived and age more rapidly than mammals. However, it has been reported that avian species have higher levels of circulating antioxidants (α -tocopherols, carotenoids, and uric acids) compared with comparably sized mammals. 3,4 Apparently birds have evolved mechanisms to limit the damage caused by the production of increased amounts of oxygen free radicals or oxidants emanating from radicals, e.g., peroxynitrite.