Distribution and activity of transglutaminase in rat brain carcinogenesis and in gliomas.

Tissue transglutaminase is a calcium-dependent enzyme which may influence cell morphology, cytoskeletal processes and membrane functions. During rat brain carcinogenesis induced by transplacental administration of N-ethyl-N-nitrosourea to BD IX rats, cytosolic tissue transglutaminase activity was increased by about 140% at 30 days of extrauterine life and returned towards the control values at 3-5 months. In the particulate fraction, enzyme activity progressively increased, reaching values similar to those present in the developed gliomas. Tissue transglutaminase activity in gliomas had a behavior inverse to that observed in controls, with a decrease (about 50%) in the cytosol and a marked increase (380%) in the particulate fraction, indicating a redistribution of enzyme activity.