title: Regulation of lymphocyte responses in vitro: potentiation and inhibition of rat lymphocyte responses to antigen and mitogens by cytochalasin B.
abstract: Cytochalasin B, at concentration between 0.02 and 0.2 mug/ml, was slightly stimulatory to lymph-node cells from normal rats and greatly potentiated their response to phytohemagglutinin and low concentrations of concanavalin A (mitogens for thymus-derived lymphocytes); it also potentiated the response of thymocytes to phytohemagglutinin. The response of lymphnode cells to lipopolysaccharide endotoxin (a mitogen for thymus-independent lymphocytes) was also enhanced, but only at concentrations in the usual inhibitory range, possibly by inhibition of a "suppressor T-cell" response. Sensitized lymphocytes responding to antigen were not stimulated at all, except at a very high cell density, where inhibition of a "suppressor cell" response was also considered likely. At concentrations of 5-10 mug/ml or higher, cytochalasin B inhibited all responses tested.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects; D003208:Concanavalin A / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D004357:Drug Synergism; D004731:Endotoxins / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008214:Lymphocytes / Q000378:metabolism; D008934:Mitogens / Q000494:pharmacology; D003904:Mitosporic Fungi; D010047:Ovalbumin / Q000494:pharmacology; D011135:Polysaccharides, Bacterial / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013601:T-Lymphocytes / Q000187:drug effects; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
chemical_list: D004731:Endotoxins; D007211:Indoles; D008070:Lipopolysaccharides; D008934:Mitogens; D011135:Polysaccharides, Bacterial; D014316:Tritium; D003208:Concanavalin A; D003571:Cytochalasin B; D010047:Ovalbumin; D004247:DNA; D013936:Thymidine