Which intracellular mediator accounts for the principal antihyperglycaemic action of metformin?

• A Closure of ATP-sensitive potassium channels in pancreatic beta cells
• B Inhibition of sodium-glucose cotransporter 2 in the proximal tubule
• C Stimulation of GLP-1 receptors on beta cells increasing cyclic AMP
• D Activation of AMP-activated protein kinase leading to reduced hepatic gluconeogenesis ✓

Explanation

Metformin activates AMP-activated protein kinase and also inhibits mitochondrial complex I and the glycerophosphate dehydrogenase shuttle, and its dominant clinical effect is suppression of hepatic gluconeogenesis, lowering fasting glucose. Option A describes the sulfonylurea receptor mechanism, option C describes incretin-based agents, and option B describes SGLT2 inhibitors such as empagliflozin.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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