Ursidae: The Undergraduate Research Journal at the University of Northern Colorado

Faculty Sponsor

Corina Brown

Second Faculty Sponsor

Richard Hyslop


Metformin is the most commonly prescribed treatment for type II diabetes. While the clinical effects of this generic drug are established, exact targets of metformin action remain unclear. The hypothesis of the present study was that metformin lowers blood glucose through inhibition of pyruvate carboxylase (PC), an enzyme catalyzing the first committed step of gluconeogenesis. Because metformin is relatively low cost, it is widely accessible to communities worldwide; currently, 150 million individuals depend on metformin for treatment. Thorough investigation of all targets involved in action of metformin becomes crucial, as it further explains the adverse effects of the drug. The specific activity of purified bovine PC was measured spectrophotometrically through the loss of absorbance at 340nm, following the oxidation of NADH. The design involved a series of enzyme-coupled assays treated with or without metformin (250-2,500 μM). Waller-Duncan post-hoc analysis revealed significant inhibition between controlled and treated groups at 500-2,500μM of metformin for the assays. Supporting results provide further insight into mechanisms of action behind metformin, as well as provide further explanation for the effects users experience.

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