Global IRS-1 phosphorylation analysis in insulin resistance.

ABSTRACT:

Aims/hypothesis

IRS-1 serine phosphorylation is often elevated in insulin resistance models, but confirmation in vivo in humans is lacking. We therefore analysed IRS-1 phosphorylation in human muscle in vivo.

Methods

We used HPLC-electrospray ionisation (ESI)-MS/MS to quantify IRS-1 phosphorylation basally and after insulin infusion in vastus lateralis muscle from lean healthy, obese non-diabetic and type 2 diabetic volunteers.

Results

Basal Ser323 phosphorylation was increased in type 2 diabetic patients (2.1 ± 0.43, p ≤ 0.05, fold change vs lean controls). Thr495 phosphorylation was decreased in type 2 diabetic patients (p ≤ 0.05). Insulin increased IRS-1 phosphorylation at Ser527 (1.4 ± 0.17, p ≤ 0.01, fold change, 60 min after insulin infusion vs basal) and Ser531

SUBMITTER: Langlais P 

PROVIDER: S-EPMC3882165 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature