title: Effects of some platinum IV complexes on cell division of Escherichia coli.
abstract: A comparison was made of the effects of cis-tetrachlorodiaminoplatinum (IV) (cis-TCDPt), rans-TCDPt), and hexachloroplatinum (HCP) on growth and cell division of Escherichia coli strains D21 and D22. At or below 40 microgram/mL, cis-TCDPt inhibited cell division but not growth, DNA, or protein synthesis, although areas of increased electron density could be demonstrated in treated cells. In contrast, 40 microgram/mL of trans-TCDPt or HCP inhibited growth. Trans-TCDPt-treated cells developed condensed nucleoids; HCP-treated cells showed no obvious cytological changes to correlate with growth inhibition. Combination of cis-TCDPt with nalidixic acid, both at one-half the lowest filament-forming concentrations, resulted in formation of filaments, suggesting an additive effect. Combination of cis-TCDPt followed by ampicillin on E. coli B/r resulted in single bulges near the center of the filaments. Cis-TCDPt could therefore inhibit an initial step in the septation sequence, possibly at the level of the regulation of the hydrolytic enzymes. Whether cis-TCDPt exerts its effect by interreaction with DNA or with a membrane target is still uncertain.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis; D002455:Cell Division / Q000187:drug effects; D004269:DNA, Bacterial / Q000096:biosynthesis; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D009268:Nalidixic Acid / Q000494:pharmacology; D009944:Organoplatinum Compounds / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D009944:Organoplatinum Compounds; D009268:Nalidixic Acid; D000667:Ampicillin