Related Experiment Video
Updated: Mar 2, 2026
The Extraction of Liver Glycogen Molecules for Glycogen Structure Determination
Published on: February 8, 2022
Comparison of Methods to Assay Liver Glycogen Fractions: The Effects of Starvation
Nastaran Mojibi1, Mehdi Rasouli2
1PhD Student, Department of Clinical Biochemistry, Mazandaran University of Medical Sciences, Sari, Mazandaran, Iran.
Introduction:
There are several methods to extract and measure glycogen in animal tissues. Glycogen is extracted with or without homogenization by using cold Perchloric Acid (PCA).
Aim:
Three procedures were compared to determine glycogen fractions in rat liver at different physiological states.
Materials And Methods:
The present study was conducted on two groups of rats, one group of five rats were fed standard rodent laboratory food and were marked as controls, and another five rats were starved overnight (15 hour) as cases. The glycogen fractions were extracted and measured by using three methods: classical homogenization, total-glycogen-fractionation and homogenization-free protocols.
Results:
The data of homogenization methods showed that following 15 hour starvation, total glycogen decreased (36.4±1.9 vs. 27.7±2.5, p=0.01) and the change occurred entirely in Acid Soluble Glycogen (ASG) (32.0±1.1 vs. 22.7±2.5, p=0.01), while Acid Insoluble Glycogen (AIG) did not change significantly (4.9±0.9 vs. 4.6±0.3, p=0.7). Similar results were achieved by using the method of total-glycogen-fractionation. Homogenization-free procedure indicated that ASG and AIG fractions compromise about 2/3 and 1/3 of total glycogen and the changes occurred in both ASG (24.4±2.6 vs. 16.7±0.4, p<0.05) and AIG fraction (8.7±0.8 vs. 7.1±0.3, p=0.05).
Conclusion:
The findings of 'homogenization assay method' indicate that ASG is the major portion of liver glycogen and is more metabolically active form. The same results were obtained by using 'total-glycogen-fractionation method'. 'Homogenization-free method' gave different results, because AIG has been contaminated with ASG fraction. In both 'homogenization' and 'homogenization-free' methods ASG must be extracted at least twice to prevent contamination of AIG with ASG.
Related Concept Videos
01:24Metabolic States of the Body: Fasting and Starvation
01:18Metabolic States of the Body: The Postabsorptive State
Initially, glycogen stored in the liver is broken down to release glucose into the bloodstream, while glycogen in the muscles is broken down to supply glucose for energy directly within the muscle cells. As glycogen stores diminish,...