Question

What type of hormone is epinephrine?

Answer 1

Hormones are chemical messengers which are synthesized by the body in trace amounts and these are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions. There are many types of hormones that act on different aspects of bodily functions and processes, for example for the development and growth, Metabolism of food etc.

Complete answer:
Epinephrine is also called adrenaline, a hormone secreted by the medulla region of the adrenal glands.
It's main function is to extend flow and to boost glucose levels in the blood.
Epinephrine is generally released during stress, so it is also called the fight or flight hormone.

Structure of epinephrine:
In this a catechol group is present which is a benzene formula with two hydroxyl groups, a nitrogen containing group(amine group) is present which is attached to catechol and a methyl group is also present on the nitrogen side chain. Due to the presence of an amine group and catechol group this is also called catecholamine along with norepinephrine.
Both epinephrine and norepinephrine are key stimulators of the sympathetic nervous system.
Epinephrine is produced specifically within the medulla region of adrenal gland, where the amino alkanoic acid tyrosine is transformed into norepinephrine through a series of reactions. An enzyme phenylethanolamine N-methyltransferase causes the methylation of norepinephrine to epinephrine; this enzyme is found within the chromaffin cells of the medulla.

Physiological actions of epinephrine:
Generally epinephrine causes constriction of blood vessels but in skeletal muscles it dilates the blood vessels. It increases heart beat and the force of contraction in heart which increases overall output of blood and raises vital signs. In the liver it breaks down glycogen to glucose due to which the level of blood glucose increases. There are various other functions which are played by epinephrine.

Note:
The discovery of Epinephrine was made in the late 1800s. English physiologists George Oliver and Sir Edward Albert Sharpey-Schafer were among the firsts to explain the blood-pressure-raising effect of a substance which is released from the medulla. In the year 1900 epinephrine had been isolated and identified by American physiological chemist John Jacob Abel and, independently, by Japanese American biochemist Jokichi Takamine. In 1904 German chemist Friedrich Stolz became the first to artificially synthesize the hormone.