Abstract
Using 3,3′-diaminobenzidine as substrate, the localization of cytochrome oxidase activity has been studied in mitochondria of brown adipose tissue from late prenatal rats. The reaction demonstrated cytochrome c oxidase since it was stimulated by exogenous cytochrome c, inhibited by KCN, and was insensitive to antimycin. The reaction product was found in the cristal and intermembrane spaces of unfixed, isolated mitochondria after as little as 2 minutes of incubation. Even after 45 minutes of incubation, reaction product was not clearly localized to the type II inclusions. This negative result was not altered by the presence of exogenous cytochrome c or by 2,4-dinitrophenol in the incubation medium. In fixed tissue, 30–40% of the mitochondrial profiles contained cristae oriented longitudinally. These had no observably different cytochrome oxidase activity compared to cristae oriented transversely. The results are discussed. It is concluded that they support the hypothesis that type II inclusions are composed of incomplete inner membrane lacking some membrane-bound respiratory enzymes.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
