Serotonin
was first recognised as a powerful vasoconstrictor in blood serum. It was
isolated in 1948 by Page and was later found to be associated with the central
nervous system.
The
chemical name for serotonin is 5-hydoxytryptamine which is often abbreviated to
5-HT.
Serotonin
is naturally produced in the Pineal gland which lies deep at the centre of the human brain. The
average adult human possesses only 5 to 10 mg of serotonin, 90 % of which is in
the intestine and the rest in blood platelets and the brain.
One
role of this 'wonder drug' is as a neurotransmitter, allowing numerous functions
in the human body including the control of appetite, sleep, memory and learning,
temperature regulation, mood, behaviour, cardiovascular function, muscle
contraction, endocrine regulation and depression. Subsequent to
his discovery of Serotonin, Page commented that no physiological substance known
possesses such diverse actions in the body as does serotonin.
5-HT
is also found in wasp stings and scorpion venom where its function is of an
irritant, since intravenous injection of serotonin in humans leads to pain,
gasping, coughing, a tingling and prickling sensation, nausea, cramps and other
unpleasant symptoms.