100 7.31 Muscle Macronutrient Metabolism
Compared to extrahepatic tissues as a whole, in the muscle the following pathways are not performed or are not important:
Fatty acid synthesis
Ketone body breakdown
These pathways are crossed out in the figure below.
Removing those pathways, the following metabolic pathways make up the muscle metabolic capability:
Glycogen synthesis and breakdown
Glycolysis
Protein synthesis and breakdown
Triglyceride synthesis and breakdown
Fatty acid breakdown
Lactate synthesis
Muscle is a major extrahepatic metabolic tissue. It is the only extrahepatic tissue with significant glycogen stores. However, unlike the liver, the muscle cannot secrete glucose after it is taken up (no glucose-6-phosphatase). Thus, you can think of the muscle as being selfish with glucose. It either uses it for itself initially or stores it for its later use.
References & Links
1. http://en.wikipedia.org/wiki/File:CellRespiration.svg