Growth lnhibition of Cultured Animal Cells with Nicotinic Acid Related Compounds

Effect of nicotinic acid related compounds on the growth of cultured animal cells was investigated. Each compound was added at various concentrations (1μM-0.1M) to the Culture medium of murine myeloid cells(P3X63‐Ag8.653), syrian hamster kidney cells (BHK-21 clone-13)and human leukemia cells(K-562). All of the compounds tested were more or less inhibitory to every cells. When compared at 10 mM, it can be summarized as below: In murine myeloid cells, trigonelline had no effect; nicotinic acid N-oxide and cinchomeronic acid were very weak inhibitors; nocotinic acid, 6-hydroxynicotinic acid, quinolinic acid, etc. were weak inhibitors; nicotinamide, isonicotinic acid hydrazide, picolinamide, pyridoxamine, N1- methylnicotinamide, pyridoxine, etc. were strong inhibitors; picolinic acid, dipcolinic acid, pyridoxal and pyridoxal 5´- phosphate were strongest inhibitors (no living cell was detectaЫe). The apparent inhibition with nicotinamide at 5 mM was recovered when the compound was removed from the medium after 48 hr incubation. On the contrary, large amount of cells were killed with other potent inhibitors at 5 mM after 48 hr incubation. In syrian hamster kidney cells, the effect of above inhibitors were generally weaker than those in murine myeloid cells. In human leukemia cells, the inhibition pattern was similar to that in murine myeloid cells with the exception of trigoneline