title: RNA synthesis in activated macrophages I. Poly(I) X poly(C)-induced triggering of cytolytic activity is associated with decrease in RNA synthesis.
abstract: The effects of polyinosinic, polycytidylic acid [poly(I) X poly(C)] on the activation and RNA metabolism in murine peritoneal macrophages (M phi) elicited by proteose-peptone (pM phi) was investigated. Poly(I) X poly(C) triggered the cytolytic activity of pM phi and augmented their glucose oxidation. In contrast, a profound depression of [3H]uridine incorporation into RNA was observed in poly(I) X poly(C)-activated pM phi. The degree of depression of RNA labeling paralleled the dose of poly(I) X poly(C) used to activate the pM phi and the expression of tumoricidal activity. This decrease in [3H]uridine incorporation into M phi RNA could not be accounted for by decreased permeability of the activated M phi to [3H]uridine, or by instability of the labeled RNA. Moreover, analysis of the specific activity of the intracellular uridine triphosphate (UTP) pool and studies on the labeling of M phi RNA with [32P] orthophosphate indicated that the decreased RNA labeling was not due to changes in the specific activity of UTP. We concluded that poly(I) X poly(C)-activated pM phi exhibit a depressed rate of RNA synthesis. We suggest that the rate of RNA synthesis may be investigated as a potential new indicator for M phi activation.
mesh_terms: D000818:Animals; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D005260:Female; D007700:Kinetics; D008262:Macrophage Activation; D008264:Macrophages / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010761:Phosphorus Radioisotopes; D011070:Poly I-C / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects*; D014316:Tritium
chemical_list: D010761:Phosphorus Radioisotopes; D014316:Tritium; D011070:Poly I-C