Related Experiment Videos
Reduced serum dipeptidyl peptidase-IV after metformin and pioglitazone treatments
James M Lenhard1, Dallas K Croom, Dana T Minnick
1Department of Metabolic Diseases, GlaxoSmithKline Inc., Research Triangle Park, NC 27709, USA. jimlenhard@hotmail.com <jimlenhard@hotmail.com>
Abstract:
Dipeptidyl peptidase-IV (DPP-IV) regulates metabolism by degrading incretins involved in nutritional regulation. Metformin and pioglitazone improve insulin sensitivity whereas glyburide promotes insulin secretion. Zucker diabetic rats were treated with these antidiabetic agents for 2 weeks and DPP-IV activity and expression were determined. Serum DPP-IV activity increased whereas tissue activity decreased as the rats aged. Treatment of rats with metformin, pioglitazone, and glyburide did not alter DPP-IV mRNA expression in liver or kidney. Metformin and pioglitazone significantly (P<0.05) reduced serum DPP-IV activity and glycosylated hemoglobin. Glyburide did not lower DPP-IV activity or glycosylated hemoglobin. Regression analysis showed serum DPP-IV activity correlated with glycosylated hemoglobin (r=0.92) and glucagon-like peptide-1 levels (r=-0.49). Metformin, pioglitazone, and glyburide had no effect on serum DPP-IV activity in vitro, indicating these are not competitive DPP-IV inhibitors. We propose the in vivo inhibitory effects observed with metformin and pioglitazone on serum DPP-IV activity results from reduced DPP-IV secretion.
Related Concept Videos
Dipeptidyl Peptidase 4 Inhibitors
Oral Hypoglycemic Agents: Biguanides and Glitazones
Glucagon-like Receptor Agonists
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...
Oral Hypoglycemic Agents: Glinides
Oral Hypoglycemic Agents: α-Glucosidase Inhibitors
Acarbose and miglitol are typically...
Type I Diabetes III: Clinical Manifestations