Cytochrome c oxidase activity in human liver specimens. An index of prognosis for hepatic resection.

Cytochrome c oxidase activity, measured as Vmax (nanomoles of cytochrome c oxidized per second per milligram of protein) and Michaelis constant (Km) (micromoles per liter), was measured spectrophotometrically in human liver specimens obtained by needle biopsy from 43 patients. In 16 normal livers, the Vmax and Km values ranged from 1.26 to 2.25 nmol/s per milligram of protein and from 2.78 to 3.95 mumol/L, respectively. In 27 patients with liver cirrhosis or chronic hepatitis, these values ranged from 1.60 to 3.80 nmol/s per milligram of protein and from 2.80 to 6.50 mumol/L, respectively. Patients with Vmax above 2.5 nmol/s per milligram of protein or Km above 5.0 mumol/L had a high incidence of postoperative complications even after minor hepatic resection. By contrast, even patients with liver cirrhosis or chronic hepatitis could tolerate major hepatic resection as long as their Vmax and Km values were within the normal range. These findings indicate that the cytochrome c oxidase activity in liver specimens can serve as a prognostic sign in hepatic resection even in patients with liver cirrhosis or chronic hepatitis.