Abstract

The effects of 1,10-phenanthroline and a zinc complex of 1,10-phenanthroline on nucleic acid synthesis were examined by noting the capcity of these agents to incorporate [methyl-3H]thymidine, or [5-3H]uridine into hepatic and splenic DNA and RNA. Within 32 hours after the intraperitoneal injection of 1,10-phenanthroline in mice, a decrease of [methyl-3H]thymidine incorporation into hepatic DNA was observed. The administration of the zinc complex of 1,10-phenanthroline decreased the incorporation of [5-3H] uridine into hepatic RNA within 24 hours and decreased the formation of [3H]DNA from [methyl-3H]thymidine in the liver within 24 and 32 hours. An increase of the isotopic incorporation into hepatic RNA and of the pool size of ATP within 2 hours after the administration of the complex was also noted. In the splenic studies, the zinc complex significantly inhibited the formation of labeled DNA and RNA at 2, 8, 24, and 32 and 2, 8 and 24 hours postinjection, respectively. A relationship exists between the results obtained from sequential treatment (zinc chloride after 1,10-phenanthroline) and those derived from the zinc complex of 1,10-phenanthroline pertaining to an inhibition of isotopic incorporation into hepatic and splenic nucleic acid.