The measurement of endogenous carbon monoxide production

Coburn RF. The measurement of endogenous carbon monoxide production. J Appl Physiol 112: 1949-1955, 2012. First published March 22, 2012; doi:10.1152/japplphysiol.00174.2012.-Recent findings that heme oxygenase-1 can be induced by oxidative stress and inflammation in many different cellular systems, and that carbon monoxide (CO) produced as a by-product of this enzyme is a signaling molecule, have generated a major research area with hundreds of studies published over the last few years. The measurement of expired CO concentration has been used in humans as a biomarker of induced heme oxygenase resulting from inflammation or oxidative stress, but a precise method of measuring endogenous CO production that can be easily used to study patients is needed. The present study describes such a method. The described method allows calculation of the rate of heme catabolism with a precision of +/- 2 mu mol/h, similar to 10% of the mean normal rate in subjects used in this investigation. This method, which is subject-patient friendly, precise, and inexpensive to perform, should be applicable to studies performed on humans with induced heme oxygenase and studies of effects of therapy for inflammatory and hemolytic diseases.