Curare
Curare is a potent plant-derived toxin, historically known for its use by indigenous South Americans to poison arrows and darts for hunting. The origins of the name are somewhat ambiguous, possibly stemming from mispronunciations of local terms that relate to its lethal qualities. Made primarily from the plants Chondrodendron tomentosum and Strychnos toxifera, curare is a thick, tarry substance that can cause paralysis when introduced into the bloodstream, leading to the inability to move or breathe. Despite its dangerous effects, curare could be safely tasted by those preparing it, as it was only harmful when entering the blood. The substance gained significant attention from European explorers in the late 16th century, with further scientific investigation revealing its mechanism of action by blocking the neurotransmitter acetylcholine, which controls muscle contractions.
In the early 19th century, curare's potential for medical use was realized, particularly in surgeries, as it allowed for controlled muscle relaxation and reduced the need for deep anesthesia. The isolation of its active ingredient, d-tubocurarine, in 1935 led to the development of safer muscle relaxants for surgical procedures, marking a major advancement in anesthesia practices. While curare is less commonly used today due to the emergence of newer neuromuscular blockers, its historical and medical significance remains notable.
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Curare
Curare is a plant-derived toxin that relaxes certain muscles in the body. It is best known as the substance that indigenous South Americans used to make darts and arrows poisonous. Hundreds of years after European explorers experienced the effects of curare from those darts and arrows, scientists discovered how it works, how to overcome its effects, and how to use it to aid surgery. Although it is no longer widely used, curare introduced a new way to administer anesthesia during surgery.
Overview
The origin of the name curare is unclear. It may be derived from a European mispronunciation of the name South American natives used for the substance. In 1594, Sir Walter Raleigh encountered local tribes in Venezuela who used the toxin as a poison on their hunting weapons. They are thought to have called it uiraery from their words meaning "bird" and "to kill." Raleigh's companions called it ourari, ourare, and worali, among other names, before it finally became curare.
The Amazonian natives made the toxin from two main plants: Chondrodendron tomentosum and Strychnos toxifera. They crushed the vines and roots and boiled them into a thick tarry substance. They would then dip the ends of their weapons into it. The arrows and darts had to be handled carefully. If a native warrior cut himself with one of his own darts or arrows, he would suffer the effects of the poison. However, the poison was toxic only if it entered the bloodstream, so those making the substance were able to taste it to judge when it was done. In addition, animals killed with poisoned arrows or darts could be eaten without harm. The drug was sometimes used to treat other conditions as well.
Spanish conquistadors and European explorers brought back tales of the mysterious substance that took the life of many of their companions. Hundreds of years later, in the early nineteenth century, English physicist and surgeon Benjamin Brodie discovered that the drug caused paralysis but did not stop the heart. German-born explorer Robert Schomburgk determined that Strychnos toxifera was a source of the substance in 1841, while French physiologist Claude Bernard discovered that it works by blocking the function of acetylcholine, a chemical in the body that controls the contraction of muscles in the skeletal system and the lungs but not the heart.
When curare enters a victim's bloodstream, it paralyzes the muscles that allow the person to move and breathe. Brodie already had discovered that if animals and people received breathing assistance via mechanical means, such as a bellows, the curare would eventually wear off, and victims would recover. The discovery of an antidote in 1900 and the isolation of curare's active ingredient, d-tubocurarine, in 1935 paved the way for the medical use of a muscle relaxant containing d-tubocurarine in 1942.
This discovery was groundbreaking for surgeons and their patients. Using curare allowed surgeons to make sure that the body would not make involuntary movements during surgery. It also allowed them to use lighter levels of anesthesia to render a patient unconscious. Both developments made surgeries safer for patients. The use of curare was generally discontinued when other neuromuscular blockers were developed in the twentieth century.
Bibliography
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