Musculoskeletal system

What is an example of a muscle relaxant?

Curare

What is curare

refers to toxic plant mixtures used as arrow poisons

Who was curare used by

Indigenous peoples of the amazonian region of south america

What were the two main plant species in curares

Loginaceae and Menispermaceae

what are the two main alkaloids found in curare and which family does it come from?

Loganiaceae contains indole alkaloids toxiferine and Menispermaceae contains isoquinoline alkaloids tubocurarine

How do the alkaloids in curare effect the human body

They are powerful muscle relaxants that paralyze the body when introduced into the blood stream - death occurs due to respiratory failure

Why can people eat animals killed by curare and not die

The active compounds have to be injected into the blood stream so eating something that was killed with it will not result in someone’s death

How are curare alkaloids obtained

Male elder of tribe take the inner stem bark and puts it through a sieve to form a concentrated that is then rolled onto dart tips and dried

History of Europeans and Amazonian indigenous peoples

European battles with them ended with their men falling to the ground in seconds of being hit with the arrow resulting in terrifying tales of their interactions, this sparked european interest and research into curare to understand how it worked and resulted in experiments.

How curare paralysis moves through the body

Face and neck, then limbs, muscle paralysis then spreads to the abdominal and respiratory regions and then to the diaphragm muscles. Death occurs within 5 minutes due to respiratory failure

What did european experiments reveal about the reversibility of curare paralysis

European scientists tested their theory by paralyzing someone and then hooking them up to artificial breathing apparatus’ and seeing that eventually the effects of the paralysis wore off and the person was completely fine, this means people can survive curare poisonings is just they don’t because the body cant last that long without oxygen

Who researched the effects of curare asa surgical muscle relaxant?

Richard Gill

Richard Gill and curare

Collected enough plant material for biochemical and clinical trials for curare as a muscle relaxant in surgery and proved successful, he was originally the only supplier to many pharmaceutical companies. He did not want to reveal his source to them but they went behind his back and found the source anyways and was able to isolate the active compounds and tubocurarine became a key piece to reduce needs for deep anesthesia in surgery. The demand for it was too high and resulted in the over harvasting of the species.

What did the shortage of tubocurarine result in?

The development of safer semi-synthetic muscle relaxants

What is the mode of action of the muscle relaxants

Neuromuscular blocking agents that compete with acetylcholine, prevents development of nerve action potential resulting in muscle relaxation and paralysis

Main types of arrow poisons

Muscle relaxing, muscle paralyzing, most are cardiac arresting

Northeast asian arrow poisons

Come fomr aconite or monkshood

Alaskan indigenous group arrow poison use

put aconite on their spears and harpoons to hunt wales and other aquatic mammals

Which neurotoxin does monkshood contain

Aconitine, highly poisonous alkaloid, induces respiratory paralysis resulting in cardiac arrest and death

Upas tree family

Mulberry family

Southeast Asian arrow poison

comes from upas tree, used in hunting and warfare

Where is upas latex contained

bark and leaves

What is the active principle of the upas tree

cardiac glycosides such as antiarin

How do cardiac glycosides effect the body

Cardiac arresting, heart failure, results in death

Amazonian rainforest

Contains two members of the Mulberry family that have latex that is biochemically similar to that of the upas tree

Central african arrow poison

members of dogbane family used as they contain latex similar to that of the upas tree that are fast acting, they also used the a species form the milkweed family that also produced a latex.

Research into cardiac glycosides

arrow poisons cardiac glycosides were investigated for treating heart failure but side effects were too much so it sparked research into safer cardica stimulants

Muscle convulsants

Members of the genus strychnine were used as powerful convulsants due to the alkaloids strychnine and brucine within them, arrow poisons using these members resulted in uncontrolled spasmodic muscle contractions and convulsions.

what part of strychnine plants are used in arrow poisons

The seeds

Where were strychnine arrow poisons used

Southeast asia and india