Regulation of lymphocyte responses in vitro. VI. -Potentiation of the response to phytohemagglutinin by cytochalasin B.
Low concentrations of cytochalasin B (CB) potentiated the DNA-synthetic response of rat lymph node cells (LNC) to PHA. Maximal potentiation was observed at suboptimal concentrations of the mitogen, less at optimal and usually none at supraoptimal concentrations. Other metabolic responses (RNA and protein synthesis) as well as the actual number of morphologically transformed lymphocytes were also enhanced. The presence of serum in the culture was an absolute requirement for CB potentiation. A maximal effect was usually obtained when CB was present from the start of the culture. However, addition of CB as late as 46 h after PHA produced a lower but consistent potentiation. The responses to PHA of thymus cells and spleen cells were respectively more and less increased by the drug than that of LNC. These results suggest that CB acts by opposing a serum-dependent cell interaction.
D000818:Animals; D001345:Autoradiography; D003571:Cytochalasin B / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005947:Glucose / Q000494:pharmacology; D066298:In Vitro Techniques; D037102:Lectins / Q000494:pharmacology*; D007930:Leucine / Q000378:metabolism; D008198:Lymph Nodes / Q000187:drug effects / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008297:Male; D012313:RNA / Q000096:biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000276:immunology; D013936:Thymidine / Q000378:metabolism; D013950:Thymus Gland / Q000276:immunology; D013997:Time Factors; D014316:Tritium; D014529:Uridine / Q000378:metabolism
D037102:Lectins; D014316:Tritium; D003571:Cytochalasin B; D012313:RNA; D004247:DNA; D007930:Leucine; D005947:Glucose; D013936:Thymidine; D014529:Uridine