Cytochalasin B. VI. Competitive inhibition of nucleoside transport by cultured Novikoff rat hepatoma cells.
Cytochalasin B competitively inhibits the transport of uridine and thymidine by Novikoff rat hepatoma cells growing in suspension culture with apparent K(i)'s of 2 and 6 microM, respectively, but has no effect on the intracellular phosphorylation of the nucleosides. Choline transport is not affected by cytochalasin B. Results from pulse-chase experiments indicate that cytochalasin B has no direct effect on the synthesis of RNA, DNA, or uridine diphosphate-sugars. The inhibition of uridine and thymidine incorporation into nucleic acids by cytochalasin B is solely the consequence of the inhibition of nucleoside transport.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002478:Cells, Cultured; D002794:Choline / Q000378:metabolism; D004273:DNA, Neoplasm / Q000096:biosynthesis; D007211:Indoles / Q000494:pharmacology*; D008113:Liver Neoplasms / Q000378:metabolism*; D009374:Neoplasms, Experimental / Q000378:metabolism; D012334:RNA, Neoplasm / Q000096:biosynthesis; D051381:Rats; D013936:Thymidine / Q000378:metabolism*; D014316:Tritium; D014529:Uridine / Q000378:metabolism*; D014539:Uridine Diphosphate Sugars / Q000096:biosynthesis
D004273:DNA, Neoplasm; D007211:Indoles; D012334:RNA, Neoplasm; D014539:Uridine Diphosphate Sugars; D014316:Tritium; D002794:Choline; D013936:Thymidine; D014529:Uridine