Measuring Glucose Uptake in Mammalian Cells Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

Abstract

By Joyce Ghali, Biochemistry

Advisor: Julio Landero

Awards: Capstone Competition: First Place Winner

Presentation ID: 274

Abstract: Glucose is the body's major source of energy; the human body requires around 160 grams of glucose per day, 120 of which are utilized by the brain alone. If left in circulation, glucose can damage blood vessels, leading to a host of complications. Thus, the detection and quantification of glucose uptake and metabolism are necessary for conducting a variety of basic physiology and biomedical research. Present research employs radiotracers and fluorescent analogs of glucose. These techniques can only measure one analyte, limiting experimental flexibility. Given its multi-channel capabilities, we developed a method using inductively coupled plasma-mass spectrometry (ICP-MS) to simultaneously measure the uptake of 13C-labeled glucose and other elements in biological samples. This method employs a cryogenic tissue pulverization and probe-assisted ultra-sonication protocol to extract 13C-glucose and other polar analytes from tissues into ultra-pure water. We have established and optimized ICP-MS tuning parameters to reliably detect 13C, even with high carbon background. Due to its ubiquity, carbon is a difficult element to analyze using ICP-MS. By using our approach, we were able to detect as little as 4 parts per million of 13C from 13C-glucose in sample. This detection capability for carbon in biological matrices is expected to provide a novel approach for the study of complex biological processes relating to carbon/glucose metabolism. Using this method, we are investigating the correlation between a sodium-dependent glucose transporter (SGLT) and Na,K,ATPase (NKA) importing glucose into the muscle in insulin-independent conditions during contraction and its implication for diabetes mellitus.