Tetraalkylammonium ions: protection of murine L1210 leukemia and bone marrow progenitor cells in vitro against mechlorethamine cytotoxicity and inhibition of the choline transport system.

In the series of tetraalkylammonium ions from tetramethylammonium to tetra-n-heptylammonium, tetra-n-pentylammonium ion was a potent protector of both murine L1210 leukemia and bone marrow progenitor cells against mechlorethamine cytotoxicity. It was also a non-competitive inhibitor of choline uptake. Phosphonium analogs of the tetraalkylammonium ions were equal to their corresponding tetraalkylammonium ions in their protection against mechlorethamine cytotoxicity and in their inhibition of choline uptake. Treatment of tumor bearing L1210 leukemia mice with the combination of tetra-n-pentylammonium ion and mechlorethamine resulted in no major improvement in survival of the tumor-bearing mice compared to mechlorethamine treatment alone.