Glutaminase in normal human tissues and in lung carcinomata.

SummaryPhosphate-dependent glutaminase (EC 3.5.1.2) was higher in human lung, kidney and liver in that order, and was in each tissue like the isozyme with low affinity for phosphate found in rat kidney but not liver. The same type of enzyme was present in surgical samples of nine human lung carcinomata in amounts covering the six-fold range from half to three times that present in normal lung. The tumors were graded according to increasing counts of mitoses and approximately in the same order by increasing degrees of histological dedifferentiation. Glutaminase contents were generally inversely proportional to the mitotic rates and degrees of dedifferentiation of the tumors.