Carnosine and skeletal muscle dysfunction in a rodent multiple sclerosis model.

Area of Science:

• Neuroscience
• Muscle Physiology
• Nutritional Science

Background:

• Muscle weakness and fatigue are key symptoms in multiple sclerosis (MS).
• Reduced muscle carnosine levels were previously observed in MS patients and a rodent MS model.
• Carnosine is an endogenous dipeptide crucial for muscle contractile function and fatigue resistance.

Purpose of the Study:

• Confirm carnosine reduction in a chronic experimental autoimmune encephalomyelitis (EAE) model.
• Characterize structural and functional muscle alterations in EAE.
• Investigate carnosine supplementation's effect on muscle carnosine levels and function in EAE.

Main Methods:

• Immunohistochemistry to assess muscle fiber structure.
• Ex vivo contractility measurements to evaluate muscle function.
• Oral carnosine supplementation in EAE rodent models at varying doses.

Main Results:

• EAE mice exhibited progressive muscle fiber atrophy and a shift to a fast-twitch phenotype.
• Muscle strength and contraction speed were reduced in EAE mice.
• Carnosine supplementation increased muscle carnosine levels but did not improve muscle strength, speed, or fatigability.

Conclusions:

• EAE mice develop significant, time-dependent muscular alterations.
• Carnosine intervention, despite increasing muscle carnosine levels, failed to enhance muscle function in the EAE model.
• Further research is needed to understand and address muscle dysfunction in MS.