Beutler B A, Cerami A
J Immunol. 1985 Dec;135(6):3969-71.
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.
重组小鼠白细胞介素1（rIL 1）以极低浓度（低于10^(-15) M）存在时，会抑制3T3-L1细胞脂蛋白脂肪酶（LPL）活性的表达。脂肪细胞系统对rIL 1的极端敏感性远远超过标准淋巴细胞激活因子检测的敏感性。然而，酶抑制并不完全；即使在微摩尔浓度下，rIL 1也只会使LPL活性降低约50%。相比之下，恶病质素（肿瘤坏死因子）在亚纳摩尔浓度下就能实现几乎完全的LPL抑制。rIL 1的浓缩溶液无法与放射性标记的恶病质素竞争3T3-L1细胞上的结合位点。向检测系统中添加特异性IL 1中和抗血清可消除rIL 1诱导的LPL抑制。rIL 1似乎能够影响脂肪细胞中LPL的表达，但显然其作用机制与恶病质素/肿瘤坏死因子不同。
