SOME EFFECTS OF PENTAMIDINE DI-ISETHIONATE ON CRITHIDIA FASCICULATA

SYNOPSIS. Growth‐inhibitory concentrations of pentamidine inhibit to a similar extent net synthesis of DNA, RNA, protein and phospholipid by washed cell suspensions of Crithidia fasciculata. The incorporation of 3H‐thymidine into DNA, 14C‐adenine into DNA and RNA and 14C‐lysine into protein is similarly inhibited. The same concentrations of drug have little or no effect on viability, motility, 1‐C metabolism, respiration or K+ content of organisms, altho they do cause increased amounts of intracellular ATP. Lysine uptake (in the absence of arginine) is, however, inhibited. At higher concentrations of drug respiration is inhibited and organisms lose K+. The mode of action of pentamidine is considered in the light of these observations and a mechanism of uptake of pentamidine into organisms is suggested. Copyright © 1969, Wiley Blackwell. All rights reserved