The simultaneous measurement of the redox state of cytochrome oxidase in heart and brain of rat in vivo by NIR.

The mutual relationship of the redox state of cytochrome oxidase in both cardiac and brain tissues were examined by the simultaneous optical measurement. The oxygenation states of cardiac and brain tissues behaved in a same manner during progressive hypoxia. We concluded that the oxygenation state of brain completely depends on the oxygenation state of cardiac tissue which determines the cardiac output.