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Isolation of Type I and Type II Pericytes from Mouse Skeletal Muscles
Published on: May 26, 2017
Phospholipid fatty acid composition in type I and type II rat muscle
W G Blackard1, J Li, J N Clore
1Department of Medicine, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298, USA.
Lipids
|February 1, 1997
Summary
Insulin resistance in Type II muscle alters phospholipid fatty acid composition, specifically in phosphatidylcholine. This suggests reduced fatty acid elongation in these membranes.
Area of Science:
- Biochemistry
- Cell Biology
- Physiology
Background:
- The fatty acid composition of membrane phospholipids in different muscle types with varying insulin sensitivity is not well understood.
- Phosphatidylcholine (PC) and phosphatidylethanolamine are key membrane phospholipids.
- Insulin-sensitive (Type I, soleus) and insulin-resistant (Type II, EDL) muscles exhibit distinct metabolic characteristics.
Purpose of the Study:
- To investigate the differences in fatty acid composition of membrane phospholipids, specifically phosphatidylcholine (PC) and phosphatidylethanolamine, between insulin-sensitive (soleus) and insulin-resistant (EDL) rat muscles.
- To determine if alterations in fatty acid elongation or oxidation contribute to observed compositional differences.
Main Methods:
- Soleus and EDL muscles were isolated from Sprague-Dawley rats.
- Quantification of total and individual phospholipid species and their fatty acid composition.
- Analysis of triglyceride and cholesterol content.
- Inhibition of fatty acid oxidation using etomoxir (carnitine palmitoyl transferase-1 inhibitor).
Main Results:
- Triglyceride content was twofold higher in soleus muscle.
- No significant differences in individual phospholipid species or cholesterol content were observed between muscles.
- A significant alteration in the PC fraction's fatty acid composition was found in EDL muscle compared to soleus.
- EDL muscle PC showed increased 16:0 and decreased 18:0, 18:1, 22:5n-3, and 22:6n-3, indicating reduced fatty acid elongation.
- Inhibition of fatty acid oxidation did not affect the fatty acid patterns in either muscle.
Conclusions:
- Type II (EDL) muscle exhibits altered phospholipid fatty acid composition, characterized by reduced elongation of both saturated and unsaturated fatty acids.
- These alterations are specifically localized to the phosphatidylcholine (PC) fraction.
- The findings suggest a specific defect in PC fatty acid metabolism in insulin-resistant muscle.
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