Aspirin inhibits serine phosphorylation of insulin receptor substrate 1 in growth hormone treated animals

In this study, we demonstrate that pretreatment with aspirin inhibits GH-induced insulin resistance. GH was observed to lead to serine phosphorylation of IRS-1, a phenomenon which was reversed by aspirin in liver, muscle and WAT in parallel with a reduction in JNK activity. In addition, our data show an impairment of insulin activation in the IR/IRS/PI(3)kinase pathway and a reduction in IRS-1 protein levels in rats treated with GH, which was also reversed in the animals pretreated with aspirin. Overall, these results provide new insights into the mechanism of GH-induced insulin resistance.