This definition appears rarely
; Liu, Kan; Kudlow, Jeffrey E. An important link has recently been shown in vivo between β-cell O-linked protein glycosylation and β-cell apoptosis, with hyperglycemia having been demonstrated to reversibly increase β-cell O-linked protein glycosylation by providing substrate for the glucosamine pathway. In contrast, the same study showed that the administration of streptozotocin to rats prior to the induction of hyperglycemia results in irreversible increases in O-glycosylation and subsequent β-cell apoptosis. In light of these data, we investigated β-cell O-glycosylation in vitro by exposing isolated rat islets to high glucose, glucosamine, or streptozotocin and analyzing the pattern of O-glycosylated proteins present. All three compounds acutely increased O-glycosylation of a predominate 135-kDa protein.