Aerobic glycolysis, oxygen uptake, and enzyme activity of the electron transport system in neoplastic and non-neoplastic ovarian tissue grafted into the spleen of C57BL mice

Abstract

Summary The lactic acid production, oxygen uptake, and activities of 5 enzymes of the electron transport system have been studied in normal ovaries, 60-day-old intrasplenic grafted ovarian tissue, and primary 12-month-old ovarian tumors developed from grafts in the spleen of C57BL mice. The 60-day-old grafted ovarian tissue, although not greatly different from normal ovaries, seems to possess quite a distinct biochemical pattern. Decreased activity in the following parameters were found: oxygen uptake, aerobic lactic acid production, reduced diphosphopyridine nucleotide oxidase, reduced diphosphopyridine nucleotide-cytochrome c reductase, reduced diphosphopyridine nucleotide ferricyanide reductase, succinate-cytochrome c reductase, and cytochrome oxidase. In the primary tumors a lower oxygen uptake coincident with a decreased level of succinate-cytochrome c reductase and cytochrome oxidase, compared with normal ovaries, was observed. Glucose utilization was displayed only by the primary tumors. The data obtained suggest that in the 60-day-old grafts a respiratory damage is operating, possibly as a first step toward the neoplastic change of the ovarian cell. Based on these findings it can be stated that the Warburg hypothesis on the origin of the cancer cell seems to be supported for the ovarian tissue in the preneoplastic stage.