Changes in plasma levels of lipid peroxidation products and myoglobin in patients with malignant tumors in the early postoperative period

: Changes in the levels of free myoglobin and lipid peroxidation products (hydroperoxides and malonic dialdehyde) were studied in cancer patients. Their baseline levels were found to be higher in patients with cancer of the lung, large bowel, and rectum than those in controls, which indicates higher lipid peroxidation, which led to the destabilization of cellular membranes and seems to cause baseline hypermyoglobinemia. There was a drastic rise in the levels of free myoglobin in the first 24 postoperative hours. The duration and severity of hypermyoglobinemia were much higher in the complicated than uncomplicated postoperative period. There was a less rise in malonic dialdehyde concentrations, whose peak was observed on days 1-2 postsurgery. The content of hydroperoxides decreased in the first 24 postoperative hours and began gradually increased from day 2. The correlation between the concentrations of myoglobin and malonic dialdehyde suggests that there is an association between hypermyoglobinemia and the status of cellular membranes.