title: Reduced in vivo biological activity of in vitro glycosylated insulin.
abstract: We evaluated the in vivo biological activity of in vitro extensively glycosylated insulin (GI) with the euglycemic-hyperinsulinemic glucose-clamp technique in postabsorptive nondiabetic subjects. Insulin-mediated glucose disposal was approximately 30% lower (P less than .03) with GI (9.2 +/- 1.2 mg.kg-1.min-1, mean +/- SE) than with the nonglycosylated hormone (12.6 +/- 0.7 mg.kg-1.min-1) at comparable plasma insulin concentrations (approximately 90 microU/ml). Binding of GI to a specific receptor on circulating cells (erythrocytes and monocytes) was normal. We conclude that in vitro extensive glycosylation of insulin reduces its biological activity in vivo, as reflected by insulin-mediated glucose disposal, probably at a postreceptor level.
authors.affiliation: Patologia Medica I., University of Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Lapolla
authors.forename: P
authors.initials: P
authors.lastname: Tessari
authors.forename: T
authors.initials: T
authors.lastname: Poli
authors.forename: A
authors.initials: A
authors.lastname: Valerio
authors.forename: E
authors.initials: E
authors.lastname: Duner
authors.forename: E
authors.initials: E
authors.lastname: Iori
authors.forename: D
authors.initials: D
authors.lastname: Fedele
authors.forename: G
authors.initials: G
authors.lastname: Crepaldi
mesh_terms: D000328:Adult; D001667:Binding, Competitive; D002096:C-Peptide / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000031:analogs & derivatives* / Q000097:blood / Q000502:physiology; D008297:Male; D009000:Monocytes / Q000378:metabolism
chemical_list: D002096:C-Peptide; D007328:Insulin; C039522:insulin, glycosylated; D005947:Glucose