(Na+ + K+)-ATPase in C6 glioma and rat cerebrum.
The content and distribution of the membrane-bound enzyme (Na+ + K+)-ATPase in a rat cerebral C6 glioma was determined by immunocytochemistry, immunoblots and enzyme assay. In the C6 glioma cell culture (Na+ + K+)-ATPase activity was about 20% of (Mg2+ + Na+ + K+)-ATPase activity. However, (Mg2+ + Na+ + K+)-ATPase activity in the cerebral C6 gliomas was very close to Mg2+ baseline and not significantly increased by Na+ and K+. As shown by immunoblotting, (Na+ + K+)-ATPase catalytic subunit was detected in excised samples of control cerebrum and as a trace in the intracerebral portions of C6 glioma but not at all in the extracranial portions of C6 glioma or in C6 glioma cell culture. (Na+ + K+)-ATPase was not detected immunocytochemically in paraffin sections of the extracranial or intracerebral portions of rat cerebral C6 glioma. The absence of staining for (Na+ + K+)-ATPase clearly demarcated projections of glioma within normal brain. These results suggest that C6 glioma has little if any expression of (Na+ + K+)-ATPase in vitro or in vivo. The small amount of enzyme epitope in the intracerebral portions represents contamination by normal cerebrum in the extracts.
D000818:Animals; D001932:Brain Neoplasms / Q000032:analysis / Q000201:enzymology*; D002460:Cell Line; D002540:Cerebral Cortex / Q000032:analysis / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D005910:Glioma / Q000032:analysis / Q000201:enzymology*; D007106:Immune Sera / Q000032:analysis; D007158:Immunologic Techniques; D009185:Myelin Proteins / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D000254:Sodium-Potassium-Exchanging ATPase / Q000032:analysis*
D005904:Glial Fibrillary Acidic Protein; D007106:Immune Sera; D009185:Myelin Proteins; D000254:Sodium-Potassium-Exchanging ATPase