Nanomolar concentrations of nitric oxide reversibly inhibit synaptosomal respiration by competing with oxygen at cytochrome oxidase

FEBS Letters

Brown, Guy C.¹  Cooper, Chris.E.² 

[1] Department of Biochemistry and Molecular Biology, University College, London, Gower Street, London WC1E 6BT, UK;Department of Paediatrics, University College, London Medical School, 5 University Street, London WC1E 6JJ, UK

关键词: Nitric oxide;    Cytochrome oxidase;    Synaptosome;    Oxygen;   

DOI  :  10.1016/0014-5793(94)01290-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Nitric oxide (NO) reversibly inhibited oxygen consumption of brain synaptosomes. Inhibition was reversible, occurred at the level of cytochrome oxidase, and was apparently competitive with oxygen, with half-inhibition by 270 nM NO at oxygen concentrations around 145 μM and by 60 nM NO at around 30μM O₂. Isolated cytochrome oxidase was inhibited by similar levels of NO. These levels of NO are within the measured physiological and pathological range for a number of tissues and conditions, suggesting that NO inhibition of cytochrome oxidase and the competion with oxygen may occur in vivo.

【 授权许可】

Unknown