Thiamine is a Vital Nutrient for the Treatment of Myasthenia Gravis
Myasthenia Gravis (MG) is described as an autoimmune neuromuscular disease that leads to debilitating muscle weakness.
It is thought that the body’s own antibodies inhibit the neurotransmitter acetylcholine (necessary for muscle movement) by blocking the receptor sites that bind acetylcholine at the neuromuscular junction.
Simply put, without acetylcholine muscles cannot contract and become flaccid (limp).
Thiamine’s role as it relates to muscle movement is assisted by thiamine pyrophosphate (TPP), the active form of thiamine. TPP is part of what is known as “Pyruvate Dehydrogenase Complex” or simply PDH complex. This complex is basically made up of three important components, TPP (from thiamine), Flavin Adenine Dinucleotide (FAD from Vitamin B2), and lipoamide.
Without thiamine (thus TPP), pyruvate could not make the conversion to acetyl-CoA (with the aid of choline, also in the B family) to become acetylcholine.
Thiamine and Muscle Contraction
It can be said that thiamine, in its active form of thiamine pyrophosphate (TPP), is directly involved with the release of the neurotransmitter acetylcholine.
As mentioned, those with MG have antibodies circulating in their system that block the receptors that bind acetylcholine, thus preventing the effect of the neurotransmitter. Because the effect of acetylcholine is stimulative, in the absence of acetylcholine, there is an inability to contract muscles.
[TPP is also known as cocarboxylase. I mention this because although the terms thiamine pyrophosphate and cocarboxylase can be used interchangeably, when it comes to research, often only one term or the other is used in a particular resource. It is important to be aware of this when performing your own research.]
The major issue surrounding MG is the accumulation of pyruvate at the neuromuscular junction. When pyruvate can’t be converted to acetylcholine, it basically has nowhere to go.
This, along with a shortage of cocarboxylase (or TPP) which is commonly found in those with MG, results in decreased amounts of acetylcholine.
A shortage of cocarboxylase is what is referred to as a thiamine deficiency.
This is why thiamine is so vital when it comes to MG!