An evaluation of the mechanism of action of pentamidine isethionate

The effect of pentamidine on DNA, RNA, phospholipid, and protein synthesis was evaluated in 6C3HED ascites tumor of C3H mice by incorporation in vitro of 3H‐thymidine, 3H‐uridine, 3H‐algal protein hydrolysate, and 32P‐orthophosphate. Inhibition of all parameters measured was observed, suggesting that pentamidine does not, as has been suggested, selectively inhibit DNA synthesis or act as an antifol. A reduced incorporation of 32P into charcoal adsorbable acid soluble phosphate was observed, suggesting that pentamidine may impair nucleotide formation.