Eunsook Jin, Ph.D.
Eunsook Jin, Ph.D., uses magnetic resonance spectroscopy (MRS) to study intermediary metabolism in vivo. Dr. Jin and her colleagues study both rodent models and humans focusing on intermediary metabolic pathways, carbohydrate/fat metabolism, obesity, and insulin resistance.
To understand the whole body metabolism, they analyze different organs including liver, skeletal muscle, and any organs that possibly affect systemic metabolism. Different types of stable isotopes are selected in their studies, typically 13C-labeled substrates, heavy water (2H2O) and 2H-labeled metabolites. After administration of tracers, blood and/or tissues of target organs are harvested for the extraction of metabolites labeled by stable isotopes for NMR analysis.
Using rodent animal models, Dr. Jin has worked on several different areas. First, she has studied hepatic glucose production in obesity-associated animal models of diabetes. She demonstrated that remaining hepatic glycogen of fasted animals was a substantial source for hepatic glucose over-production and subsequently contributed to fasting hyperglycemia. Second, Dr. Jin has investigated intermediary metabolic pathways using 13C labeled tracers.
One of her findings was the presence of revere pyruvate kinase pathway in skeletal muscle. The pathway was thought not to occur in vivo previously, but Dr. Jin and her colleagues showed the evidences of the pathway in animal models. Dr. Jin has also been interested in methodology development to prove intermediary metabolism in vivo. She introduced a new tracer, [3,4-13C2]glucose, for the detection of whole body glucose turnover. One of the advantages of the tracer is simultaneous administration with other common isotope tracers to estimate complete hepatic glucose production profiles.
Under supervision of Dr. Jin, a clinical study is underway to figure out how supporting fluxes of hepatic glucose production and systemic glucose homeostasis are altered in obese men and obese diabetic patients. Liver fats are measured using 1H-MRS with 3T MRI scanner. After that, hepatic glucose production profiles are measured under both basal and hyperinsulinemic conditions. This is an advanced technique by combining hyperinnsuilnemic-euglycemic clamps and multiple stable isotope administration.
In this study, three groups of men are participated: lean controls, obese non-diabetic controls and obese type 2 diabetic patients. One of most promising data through this study will be identifying the change of each subflux of glucose production from basal to hyperinsulinemic transition, which is important to improve our understanding about hepatic insulin resistance.
For publication information please view Dr. Jin's faculty profile.