title: Recombinant interleukin 1 suppresses lipoprotein lipase activity in 3T3-L1 cells.
abstract: Recombinant murine interleukin 1 (rIL 1) inhibits 3T3-L1 cell expression of lipoprotein lipase (LPL) activity when present in exceedingly dilute concentration (less than 10(-15) M). The extreme sensitivity of the adipocyte system to rIL 1 far exceeds that of the standard lymphocyte-activating factor assay. However, enzyme suppression is incomplete; even at micromolar concentrations, rIL 1 causes only about a 50% reduction in LPL activity. By contrast, cachectin (tumor necrosis factor) achieves nearly complete LPL suppression at subnanomolar concentrations. Concentrated solutions of rIL 1 are incapable of competing with radiolabeled cachectin for binding sites on 3T3-L1 cells. rIL 1-induced LPL suppression is abolished by the addition of a specific IL 1 neutralizing antiserum to the assay system. rIL 1 appears capable of influencing adipocyte expression of LPL, but apparently acts through a different mechanism than cachectin/TNF.
mesh_terms: D000273:Adipose Tissue / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D006023:Glycoproteins / Q000378:metabolism; D007106:Immune Sera / Q000494:pharmacology; D007375:Interleukin-1 / Q000276:immunology / Q000502:physiology*; D008071:Lipoprotein Lipase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051379:Mice; D011506:Proteins / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D018110:Receptors, Lipoprotein; D011994:Recombinant Proteins / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha
chemical_list: D006023:Glycoproteins; D007106:Immune Sera; D007375:Interleukin-1; D011506:Proteins; D011956:Receptors, Cell Surface; D018110:Receptors, Lipoprotein; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D008071:Lipoprotein Lipase