title: DNA topoisomerase activities in concanavalin A-stimulated lymphocytes.
abstract: Topoisomerase activities have been measured in nuclear extracts of concanavalin A-stimulated lymphocytes. In parallel with the wave of DNA synthesis, type II topoisomerase activity was considerably increased. After 72 h treatment, this activity was stimulated approx. 20-fold over the activity in untreated cells. In contrast, type I topoisomerase was poorly stimulated after 24 h treatment, and 4-5-fold after 72 h. These findings, together with our previous results on regenerating rat liver, suggest a major role of topoisomerase II in DNA replication.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology; D003208:Concanavalin A / Q000494:pharmacology*; D004261:DNA Replication; D004264:DNA Topoisomerases, Type I / Q000097:blood*; D004587:Electrophoresis, Agar Gel; D006168:Guinea Pigs; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000201:enzymology*; D013997:Time Factors
chemical_list: D003208:Concanavalin A; D004264:DNA Topoisomerases, Type I