Plasma retinol binding protein 4 (RBP4), Interstitial retinol binding protein 4, RBP.
Retinol binding protein (RBP4) belongs to the lipocalin superfamily of proteins. It is synthesized and secreted by hepatic paraenchymal cells and is involved in the binding of retinol and transthyretin preventing loss by glomerular filtration and renal excretion before transport to the peripheral tissues. Increased plasma levels of retinol binding protein have been shown to cause systemic insulin resistance and as such, the protein may play a role in the pathogenesis of Type II diabetes.
