The drug metformin is an effective treatment for the hyperglycemia associated with diabetes. One of the major sites of action for metformin is the liver and its use is ideal for obese patients and for younger Type 2 diabetics with normal liver function. Given that the drug lowers circulating levels of glucose, which of the following hepatic enzymes is most likely activated as a consequence of metformin administration?

Question

Quizplus · Accepted Answer

Metformin primarily activates AMP-activated protein kinase (AMPK) in the liver, which helps reduce glucose production and improve insulin sensitivity. Metformin exerts part of its effects by modulating mitochondrial activities. Metformin has a mild inhibitory effect on complex I of oxidative phosphorylation, has antioxidant properties, and activates both glucose-6-phosphate dehydrogenase (G6PDH) and AMPK. The importance of AMPK in the actions of metformin stems from the role of AMPK in the regulation of both lipid and carbohydrate metabolism. The activation of AMPK by metformin is likely related to the inhibitory effects of the drug on complex I of oxidative phosphorylation. This would lead to a reduction in ATP production and, therefore, an increase in the level of AMP and as a result activation of AMPK.

The Drug Metformin Is an Effective Treatment for the Hyperglycemia