Ascites is a metabolic disorder of modern broilers that is distinguished by cardiopulmonary insufficiency in the face of intense
oxygen demands of rapidly growing tissues. Broilers with
ascites exhibit sustained elevation of pulmonary arterial pressure and
right ventricular hypertrophy, the end result of which is
heart failure. It has been shown that mitochondrial function is impaired in broilers with
ascites. In the current study, mitochondrial matrix
protein levels were compared between
ascites-resistant line broilers and
ascites-susceptible line broilers with and without
ascites using two-dimensional (2-D) gel electrophoresis. One hundred seventy-two
protein spots were detected on the
gels, and 9 of the spots were present at different levels in the 4 groups of broilers. These 9
protein spots were selected for identification by mass spectrometry. Two of the spots were found to contain single mitochondrial matrix
proteins. Both mitochondrial matrix
proteins, the
dihydrolipoamide succinyltransferase component of the
2-oxoglutarate dehydrogenase complex and the alpha-subunit of mitochondrial trifunctional
enzyme, were present at higher levels in
ascites-resistant line broilers with
ascites in the present study. The elevated levels of 2 key
proteins in aerobic metabolism in
ascites-resistant line broilers with
ascites observed in the present study suggests that the mitochondria of broilers with this disease may respond inappropriately to
hypoxia.