Mechanisms underlying the rapid degradation and elimination of the incretin hormones GLP-1 and GIP.
The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP, gastric inhibitory peptide) are secreted from intestinal L and K cells and stimulate insulin secretion from pancreatic beta cells. However, they are immediately inactivated mainly via N-terminal degradation by dipeptidyl peptidase IV (DPP IV, CD26), a specialised enzyme located on the cell surface enzyme of endothelial, epithelial and some other cell types. Cleavage by neprilysin (neutral endopeptidase) is a minor degradation route, and renal clearance eliminates incretin/fragments, but appears of less importance for regulating incretin bioactivities. Based on these observations two novel types of drugs for the treatment of type 2 diabetes have been developed: DPP IV inhibitors and DPP IV-resistant incretin analogues. Both have distinct advantages and disadvantages. Potential side effects of DPP IV inhibitors may result from affecting the bioactivity of other hormones, neuropeptides or chemokines and also by their cross-reactivity with DPP IV-related enzymes.
Mentlein
Rolf
R
Department of Anatomy, University of Kiel, Olshausenstrasse 40, 24098 Kiel, Germany. rment@anat.uni-kiel.de
D000595:Amino Acid Sequence; D000818:Animals; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D005749:Gastric Inhibitory Polypeptide / Q000378:metabolism*; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000502:physiology; D006801:Humans; D054795:Incretins / Q000378:metabolism*; D015260:Neprilysin / Q000378:metabolism; D009478:Neuropeptide Y / Q000378:metabolism; D019894:Peptide YY / Q000378:metabolism
D054795:Incretins; D009478:Neuropeptide Y; D019894:Peptide YY; D007987:Gonadotropin-Releasing Hormone; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D018819:Dipeptidyl Peptidase 4; D015260:Neprilysin