1. Metformin, phenformin, and galegine inhibit complex IV activity and reduce glycerol-derived gluconeogenesis
- Author
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Traci E. LaMoia, Gina M. Butrico, Hasini A. Kalpage, Leigh Goedeke, Brandon T. Hubbard, Daniel F. Vatner, Rafael C. Gaspar, Xian-Man Zhang, Gary W. Cline, Keita Nakahara, Seungwan Woo, Atsuhiro Shimada, Maik Hüttemann, and Gerald I. Shulman
- Subjects
Glycerol ,Multidisciplinary ,Pyridines ,Gluconeogenesis ,Glycerolphosphate Dehydrogenase ,Guanidines ,Metformin ,Electron Transport Complex IV ,Glucose ,Liver ,Phenformin ,Animals ,Hypoglycemic Agents ,Oxidation-Reduction - Abstract
Significance Metformin is the most commonly prescribed drug for the treatment of type 2 diabetes mellitus, yet the mechanism by which it lowers plasma glucose concentrations has remained elusive. Most studies to date have attributed metformin’s glucose-lowering effects to inhibition of complex I activity. Contrary to this hypothesis, we show that inhibition of complex I activity in vitro and in vivo does not reduce plasma glucose concentrations or inhibit hepatic gluconeogenesis. We go on to show that metformin, and the related guanides/biguanides, phenformin and galegine, inhibit complex IV activity at clinically relevant concentrations, which, in turn, results in inhibition of glycerol-3-phosphate dehydrogenase activity, increased cytosolic redox, and selective inhibition of glycerol-derived hepatic gluconeogenesis both in vitro and in vivo.
- Published
- 2022