Crosstalk of glycoprotein 130 (gp130) cytokines in 3T3-L1 adipocytes. Fully differentiated 3T3-L1 adipocytes received no pretreatment (CTL, control) or were preincubated with 1 nmol/l cardiotrophin-1 (CT-1) (a), 1 nmol/l leukemia inhibitory factor (LIF) (b,d), or 1 nmol/l neuropoietin (NP) (c) for 3 h, 6 h, 8 h, or 24 h Next, the cells were treated for 10 min with 1 nmol/l CT-1, 1 nmol/l LIF, 1 nmol/l murine oncostatin M (mOSM), or 1 nmol/l NP. After the acute treatment, whole cell extracts were prepared and 150 μg of each extract was separated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis, transferred to nitrocellulose, and subjected to western blot analysis. The data in d is generated from the same exposure of the same blot. This is a representative experiment performed independently four times. MAPK, mitogen-activated protein kinase; STAT, signal transducer and activator of transcription.