A Comparison of Mitochondrial Respiratory Function of Tibet Chicken and Silky Chicken Embryonic Brain

ABSTRACT The Tibet chicken lives in high altitude and has adapted itself well to hypoxia. The Silky chicken is a lowland chicken from Jiangxi province of China. The objective of the present study was to investigate whether there were any differences in brainmitochondrial respira-tory function between Tibet chicken and Silky chicken embryos incubated in a normoxic (21 % oxygen concentra-tion) or simulated hypoxic (13 % O2) hatchibator. Brain mitochondria of chicken embryos were prepared by dif-ferential centrifugation on d 16 of incubation. The respira-tory control ratio (RCR) and the adenosine 5′-diphos-phate:oxygen ratio (ADP/O) were determined polaro-graphically. The complex I activity was measured with an ultraviolet spectrophotometer by following the oxida-tion of the reduced state of β-nicotinamide adenine dinu-cleotide. Under the normoxic incubation condition, there were no significant differences in the RCR, the ADP/O, and the activity of complex I between embryonic brain mitochondria of the 2 breeds. Under the hypoxic incuba-tion condition, the ADP/O in brain mitochondria of em