ISOLATION OF A POST-BINDING INHIBITOR OF INSULIN ACTION FROM THE SERA OF NON-INSULIN-DEPENDENT DIABETICS

Abstract

We have reported that sera from a majority of patients with non-insulin-dependent diabetes mellitus (NIDDM) inhibit insulin-stimulated lipogenesis (3-3H-glucose conversion to 3H-lipid) in rat adipocytes to a greater extent than control sera or sera from patients with insulin-dependent diabetes mellitus (IDDM). This effect was apparently due to a circulating, low molecular weight (Mr) substance soluble in acid/ethanol and resistant to proteases. We now describe the further characterization of this inhibitor isolated uniquely from NIDDM sera. Size exclusion chromatography of acid/ethanol extracts of sera on a Bio-Rad P2 column revealed the presence of a Mr 300-400 inhibitor of insulin-stimulat..