The messenger acetylcholine plays an important role within the human body because it is used in numerous processes in the central nervous system and in the autonomic nervous system. In the treatment of Alzheimer's patients, preparations are used which have an indirect influence on the active substance by inhibiting the enzyme responsible for its degradation. As a direct active ingredient, acetylcholine is used in ophthalmology in surgical procedures on the eye. This is the case when a rapid narrowing of the pupil is necessary for the procedure.

What is acetylcholine?

As a direct active ingredient acetylcholine is used eg in ophthalmology in surgical procedures on the eye.

Acetylcholine is one of the most important neurotransmitters in the human organism. This active ingredient is a quaternary ammonium compound that was discovered in 1921 as a neurotransmitter.

The pharmacologist Otto Loewi had experimented with frog hearts and discovered that the heart rate is not controlled solely by electrical transmission. Because the fluid from the environment of the heart in any frog had stimulated the heartbeat in any other frogs. When he searched for the reason, he came across the neurotransmitter.

This was initially called Vagusstoff. Henry Hallett Dale, who had also worked on the chemical transmission of nerve impulses, later defined the drug as acetylcholine. For their basic research Dale and Loewi were awarded in 1936 together with the Nobel Prize for Medicine.

Pharmacological action

Acetylcholine plays a key role in the motor endplate, where excitatory states are transmitted from the nerve fiber to the adjacent muscle fiber. In addition, the active ingredient ensures the transmission of stimuli between the nerve cells of the autonomic nervous system.

Acetylcholine occurs here both in the sympathetic and in the parasympathetic nervous system. Also in the central nervous system, the drug plays an important role as a transmitter.

Cognitive processes, for example, only work smoothly if there is a sufficiently high concentration of acetylcholine. This becomes clear, for example, in Alzheimer's disease. This neurodegenerative disease, which primarily affects older patients, is associated with the death of neurons that produce acetylcholine.

This acetylcholine deficiency is thereby counteracted in Alzheimer's therapy by administering acetylcholine estrogen inhibitors. This enzyme is thereby inhibited to split acetylcholine to acetic acid and choline. Because acetylcholine acts on a variety of receptors, including those that are stimulated by nicotine, it is believed that acetylcholine is also important for the learning process and the drive. However, proof is still missing from empirical studies.

Medical application & use

Acetylcholine is administered exclusively in ophthalmology, among other things, to narrow the dilated pupil after surgery. Basically, the drug is used when interventions are made on the anterior portion of the eyes and for a rapid and complete constriction of the pupil is necessary. Because physiologically, the tightness is triggered by the autonomic nervous system, provided that sufficient strong light impulses hit the eye.

Another field of application are so-called cataract surgery on the eye. This term is popularly known as cataract, because in an advanced stage cataract, a gray color behind the pupil becomes visible. Every year, around 650, 000 surgeries are performed in Germany in which the clouded lens is replaced by an artificial implant. These surgeries are among the most common surgical procedures on the eye.

The characteristic symptoms of cataracts include the slow and painless loss of visual acuity. In addition, the affected patients see much only blurred and suffer from an increasing glare sensitivity. This results from the fact that the light is very diffusely broken by the turbidity. Acetylcholine is also used in the so-called Iridketomie. In this procedure, a puncture is made at the edge of the cornea, which can be removed adhesions.

Risks & Side Effects

There are no direct side effects with acetylcholine. However, among other things, it may not be included in cosmetic products due to its pupil-narrowing effect. This is stated in the EU Cosmetics Directive, which was adopted in 1976. Tags: 

  • symptoms 
  • to travel 
  • counselor 
  • active ingredients 
  • Food 
  • Top