Na+/K+ ATPase and cell growth IV: a metabolic marker of human brain tumors?

The activity of total, Mg++ dependent and Na+/K+ ATPase as well as the content of cAMP and cGMP in homogenates of human brain tumors have been investigated. Results are compared to values obtained from normal cortices. Na+/K+ ATPase and cAMP are decreased with a close relationship with the degree of malignancy, while Mg++ dependent activity is lower than in normal cortex but with no differences between the various tumors, and cGMP is unaffected. We conclude with a discussion on the metabolism of brain tumors and the suggestion of Na+/K+ ATPase activity as a marker of the malignancy of neoplastic growth.