Vascular Participation in Tumor Slice Metabolism ∗

Abstract

Summary

Tissue slices from mammary carcinoma and diverse normal tissues of mice of different strains were incubated in TTC solutions with and without fluoride, malonate, azide and succinate. Frozen section examination after such treatment revealed formazan deposition in the vasculature and stroma of the tumor but none in the tumor cells, themselves. This manifestation of dehydrogenase activity in the stromal vessels was not inhibited by fluoride, malonate or azide; a finding confirmed by quantitative determinations of μ of TTC reduced per mg of acetone dried tumor tissue. No such stromal dehydrogenase activity was found in slices of normal mammary parenchyma, adrenal cortex or medulla, kidney, liver, skin or lymph node. These findings are discussed in terms of a unique function of tumor capillaries.