A Comparative Study between Rats and Pigeons and their Mitochondrial Reactive Oxygen Species Production and Tolerance to the Reactive Oxygen Species

Abstract

Aging differences between pigeons and rats have been related to a number of factors which include the production of Reactive Oxygen Species (ROS), sensitivity to inhibition caused by ROS (oxidative stress) and length of telomeres. The Maximum Lifespan Potential (MSLP) for a pigeon is 35 years where as a rat of the same mass has a MSLP of 5 years. There is evidence that elevated levels of oxidative stress impacts the MSLP of an animal. There have been studies in the past which show rats producing larger volumes of ROS and pigeons produce lower volumes. Those studies however, did not replicate conditions found in vivo, this project was carried out to mimic those conditions including physiological temperature, keeping tissues intact (not isolating the mitochondria), and using a range of substrates and inhibitors. The results produced by examining the samples under these conditions, challenge the findings of previous studies. Results show that pigeons produce more ROS in general compared with rats and are also more sensitive to inhibition by Hydrogen Peroxide (H2O2). There is also evidence that suggests increased oxidative stress and lowered glucose levels also increases MSLP of an animal and this agrees with the results found in this project. It is speculated that a larger ROS production is the reason why birds such as the pigeon, live so much longer than mammals of the same mass.