Related Experiment Video
Updated: Dec 1, 2025

Fiber Type and Subcellular-Specific Analysis of Lipid Droplet Content in Skeletal Muscle
Published on: June 8, 2022
Muscle-Liver Trafficking of BCAA-Derived Nitrogen Underlies Obesity-Related Glycine Depletion
Phillip J White1, Amanda L Lapworth2, Robert W McGarrah3
1Sarah W. Stedman Nutrition and Metabolism Center, Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA; Departments of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA; Division of Endocrinology, Department of Medicine, Duke University Medical Center, Durham, NC, USA.
Abstract:
Glycine levels are inversely associated with branched-chain amino acids (BCAAs) and cardiometabolic disease phenotypes, but biochemical mechanisms that explain these relationships remain uncharted. Metabolites and genes related to BCAA metabolism and nitrogen handling were strongly associated with glycine in correlation analyses. Stable isotope labeling in Zucker fatty rats (ZFRs) shows that glycine acts as a carbon donor for the pyruvate-alanine cycle in a BCAA-regulated manner. Inhibition of the BCAA transaminase (BCAT) enzymes depletes plasma pools of alanine and raises glycine levels. In high-fat-fed ZFRs, dietary glycine supplementation raises urinary acyl-glycine content and lowers circulating triglycerides but also results in accumulation of long-chain acyl-coenzyme As (acyl-CoAs), lower 5' adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in muscle, and no improvement in glucose tolerance. Collectively, these studies frame a mechanism for explaining obesity-related glycine depletion and also provide insight into the impact of glycine supplementation on systemic glucose, lipid, and amino acid metabolism.
More Related Videos
08:04Isolation of Primary Mouse Hepatocytes for Nascent Protein Synthesis Analysis by Non-radioactive L-azidohomoalanine Labeling Method
Published on: October 23, 2018
10:17An Advanced Murine Model for Nonalcoholic Steatohepatitis in Association with Type 2 Diabetes
Published on: April 26, 2019
Related Concept Videos
Muscle Recovery and Fatigue
Overview of Protein Metabolism
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Overview of Lipid Metabolism
Lipolysis: The Breakdown of Lipids:
Lipolysis is the process of breaking down lipids, particularly triglycerides, into glycerol and fatty acids. This process typically occurs in the adipose tissue and is triggered by various hormones, including glucagon and...
Pharmacokinetics in Obese Patients: Drug Metabolism and Excretion
Liver Physiology
Metabolic Regulation:
The liver is the central organ involved in regulating blood composition. It stabilizes blood glucose levels, maintaining them within the range of 70–110 mg/dL. When these levels drop, the liver breaks down glycogen reserves and releases glucose into the bloodstream. It can...
Metabolic States of the Body: Fasting and Starvation