SOCS-3 is involved in the downregulation of the acute insulin-like effects of growth hormone in rat adipocytes by inhibition of Jak2/IRS-1 signaling

Abstract

One of the long-term effects of growth hormone (GH) in adipocytes is to maintain a state of refractoriness to insulin-like effects, a refractoriness which otherwise declines within a few hours of GH starvation. Here, we examined differences in GH signaling and the possible role for the recently identified family of suppressors of cytokine signaling (SOCS) proteins in the transition between the refractory and the responsive states in rat adipocytes. The ability of GH to stimulate lipogenesis and tyrosine phosphorylation of the GH receptor (GHR), Janus kinase 2 (Jak2), insulin receptor substrate-1 (IRS-1) and -2 (IRS-2) was greatly reduced in refractory as compared to responsive primary rat ad..