Simultaneous measurement of mitochondrial and microsomal cytochrome levels in human liver biopsy

Abstract

The mitochondrial and microsomal cytochromes in patients' livers obtained from needle biopsies have been analyzed using a sensitive spectrophotometric method. To determine simultaneously the concentration of these cytochromes from hemoglobin-contaminated liver, difference spectra of liver homogenates were taken at the temperature of liquid nitrogen before and after photolysis of carbon monoxide molecules from various hemoprotein-CO complexes. This method utilizes a characteristic property of hemoprotein-CO complexes, in which the reassociation of CO molecules with photolyzed hemoglobin, cytochrome P-450 and cytochrome alpha3 is temperature-dependent. The results in 69 cases with a variety of liver diseases have revealed that the concentrations of cytochromes alphaalpha3, P-450 and beta5 showed a huge variation in the injured livers as compared with those in the normal controls. The significance of the measurement of these cytochrome concentrations and their ratios is discussed.