Curare

Modified: 2020-06-09

Curare, a South American poison, has its effect because it inhibits the action of an enzyme, cholinesterase. The effects of curare are muscular and respiratory paralysis. You may infer then, that the voluntary muscles and the lungs are controlled by the neurotransmitter, acetylcholine, abbreviated ACh. Curare does not affect neurons that are not controlled by ACh. Curare kills by causing all of the neurons that control breathing to be stuck open. Many of the nerve agents that the allied armed forces were concerned about during the Gulf War work in a similar fashion to curare.

The movie, "The Emerald Forest," a true story about a child abducted and raised by Brazilian Indians, contains a scene in which the child and his adoptive father go monkey hunting. They find a monkey, and carefully prepare a blowgun dart by dipping it in the curare, which they carry on a pouch around their necks. They shoot the monkey, and hit it on the foot; then they wait. As the poison takes effect, the monkey stiffens, then falls to the ground. The two hunters then walk up to the monkey and kill it. Presumably, the monkey is able to see them as they walk up and then hit it on the head.

If care is taken to keep the lungs working by artificial means, then curare will not be fatal. Before the widespread use of anesthetics, curare was routinely used in surgery. Patients were kept alive by artificial lungs until the curare dose wore off. The curare was used not as anesthetic but as a means of immobilizing the patient while the surgery took place.

Back to Chapter 3 Lectures