PYRUVATE-KINASE AND ITS INHIBITION BY L-ALANINE - CLINICAL IMPORTANCEIN HUMAN BRAIN-TUMORS

We studied pyruvate kinase activity and its inhibition by alanine in 3 3 human brain tumours and nine normal adult blain tissues. With the ex ception of two schwannomas, there were no significant differences betw een the specific pyruvate kinase activities of tumours and of normal b rain tissues. Residual pyruvate kinase activities of tumours were sign ificantly lower than those of adult brain. The lowest residual activit y was in metastatic adenocarcinomas (less than 15%). All patients suff ering from metastatic adenocarcinomas died within 6 months after the o peration. Astrocytomas of grade II and grade III showed relatively hig h residual pyruvate kinase activity. The reverse was found for gliobla stomas. There was no correlation between the histological classificati on and residual pyruvate kinase activity in meningiomas. Our data sugg est that alanine inhibition of pyruvate kinase can correlate with the histological grade of gliomas and postoperative survival of patients w ith brain tumours.