Choice of vincristine or 6-mercaptopurine on the basis of polyamine level in tumor-bearing regions of the brain.

The effects of vincristine (VC) and 6-mercaptopurine (6-MP) on body weight, regional weights, and the contents of putrescine, spermidine, and spermine in six regions of the brain were examined in rats that had been given these drugs for 5 consecutive days. VC is recommended for management of tumors in the corpus striatum and/or hippocampus, and cortex although its efficacy is dependent on the doubling time of the tumor cells, whereas 6-MP is recommended for the management of tumors in the cortex, thalamus and/or hypothalamus, and diencephalon. VC and 6-MI are chosen for treatment of the brain tumors because they reduce polyamines which are associated with the reduction of drug-sensitive cells and an inhibition of tumor growth.