Acetylcholine

What is acetylcholine?

Acetylcholine is formed from the molecules choline and acetyl-CoA and is stored in special vesicles. When a nerve cell is excited, it releases acetylcholine into the synaptic cleft, where it binds to specific receptors on the next cell. This transmits or inhibits the excitation, depending on which type of receptor is activated.

There are two main types of acetylcholine receptors: nicotinic and muscarinic. Nicotinic receptors are primarily involved in the transmission of signals between motor nerve cells and skeletal muscles. They are also responsible for the effect of nicotine , which binds to these receptors and stimulates them.

Muscarinic receptors are primarily involved in the regulation of internal organs such as the heart, lungs, gastrointestinal tract and bladder. They are also responsible for the action of muscarinic receptors, which bind to these receptors and inhibit them.

How does acetylcholine affect your dog?

Acetylcholine has many positive effects on your dog. For example, it helps him

• remember and learn
• to be alert and attentive
• sleep well
• move his muscles
• regulate his heart rate
• promote digestion
• control your bladder

However, too much or too little acetylcholine can also cause problems. For example, overproduction or hypersensitivity to acetylcholine can lead to symptoms of poisoning , which can be triggered by certain plants (e.g. belladonna), fungi (e.g. fly agaric) or insecticides (e.g. organophosphates).

The symptoms of such poisoning can be

• Salivation
• vomiting
• diarrhea
• cramps
• shortness of breath
• palpitations
• Loss of consciousness

Conversely, underproduction or hypersensitivity to acetylcholine can lead to muscle weakness caused by a rare condition called myasthenia gravis. In this case, antibodies are formed against the body's own acetylcholine receptors, which block or destroy them.

The symptoms of such a disease can be

• Difficulty swallowing
• Hoarseness
• Drooping eyelids
• Weak jaw muscles
• Flaccid tail
• Megaesophagus (abnormally dilated oesophagus)

How can you support your dog?

If you suspect that your dog is suffering from poisoning or a condition related to his acetylcholine levels, you should take him to the vet immediately. They will be able to make an accurate diagnosis and initiate the appropriate treatment.

Depending on the case, this treatment may consist of, for example

• Administration of antidotes such as atropine or pralidoxime, which inhibit or reduce the effect of acetylcholine
• Administration of medication such as diazepam or barbiturateswhich alleviate the convulsions
• Administration of infusions, which acidosis (acidosis)
• Administration of antibioticsif a bacterial infection is present
• Supporting breathing by administering oxygen or ventilation
• Nutritional support through a feeding tube or parenteral feeding

To avoid poisoning, you should make sure that your dog does not have access to poisonous plants, fungi or insecticides. If you use such substances, you should keep them safe and keep your dog away.

If your dog suffers from myasthenia gravis, he may be treated with medication that increases acetylcholine levels or suppresses antibody production. For example:

• Administration of cholinesterase inhibitors such as pyridostigmine or neostigmine, which slow down the breakdown of acetylcholine
• Administration ofimmunosuppressants such as prednisolone or azathioprine, which dampen the immune system
• Administration of antibiotics and proton pump inhibitors in the case of megaesophagus-related aspiration pneumonia
• Adjustment of feeding position and frequency in the case of megaesophagus

To diagnose myasthenia gravis, a blood test for acetylcholine receptor antibodies can be performed. There is also a special test called the Tensilon test, in which a cholinesterase inhibitor is injected and a short-term improvement in symptoms is observed.