Video: Acetylcholinesterase inhibitors
This is a video of 1 min and 33 seconds, showing an illustration of how acetylcholinesterase inhibitors work in the human body. This can be a useful video if you teach about pesticides and their health effects.
To understand the side effects of pesticides classified as “acetylcholinesterase inhibitors”, you need to know that we have a part of the nervous system which is called the autonomic nervous system. This part of the nervous system functions without need of our conscious decisions, and is for instance controlling our temperature by sweating, the pupil opening of the eyes, the moisture in eyes and mouth, as well as digestion of food in the stomach and guts. The autonomic nervous system also controls heart beats and respiration.
Look at the drawings in the slide show (video). Normally, some of our autonomic nerves transmit their signals by the use of a substance called acetylcholine (AC). A nerve may send out AC to tell the next nerve to react. By this system, the nerves function like electric wires, sending signals from one nerve to the next nerve and so on. When the signal is sent, we have an enzyme, acetylcholinesterase (ACE) that breaks down the AC, so the signal stops when it is not needed anymore. The acetyl and choline is then brought back to the nerve and can be used again next time. However, if a person is exposed to a pesticide, such as organophosphates (acetylcholinesterase inhibitor), the enzyme ACE is inhibited, and AC is not removed as normal. The nerve signal continues although it might not be needed at all. A symptom of this type of intoxication is therefore that the eyes become too moist, and tears are running, even though the person is not crying due to sadness. Other symptoms are more serious, like blurring of vision, gastrointestinal cramps, respiratory problems and excessive sweating.
This is useful knowledge because this makes it easier to understand the many different symptoms that develop when persons are intoxicated by these types of pesticides. The information can also be used to understand how this type of intoxication can be treated. The two groups of insecticides called organophosphates and carbamates are classified as acetylcholinesterase inhibitors.