Mitochondrial O 2 uptake measurement using an electronic differentiator.

Abstract

The article describes a system for the continuousin vitro mitochondrial O2 uptake measurement. This device employs a Clark-type polarographic polypropylene-corvered electrode. Four experimental parameters, set digitally from the front panel, enter into the calculation of results: 1. reaction-medium O2 concentration per ml, 2. reaction-medium volume, 3. initialpO2, and 4. mitochondrial protein content. Thus instantaneous and continuous recording ofpO2 and of O2 uptake is possible with a fixed scale for all experimental situations. An O2 uptake of 400n At O2/h·mg of mitochondrial protein would be expressed by one cm of recorder deflection. This is accomplished by an electronic differentiator with additional circuits for the introduction of parameter values. Moreover two values ofpO2 simulation (0 or 160 mm Hg) and two values of O2 uptake simulation are provided by an internal device to allow easy recorder calibration. The measurements are reproducible and the fixed scale allows easy comparison of several recordings.