Epinephrine or adrenaline, as it is popularly known is a hormone secreted by the adrenal glands released in times of stress. It is used in the treatment of certain heart problems, asthma and allergic reactions. Effects of epinephrine on the body are phenomenal and wide ranging.
Did You Know?
People who deliberately put themselves in high risk, life-threatening situations for the high induced by epinephrine are dubbed as adrenaline junkies. This includes rock climbers, skydivers, bungee jumpers and all adventurers, who live life dangerously.
Much of what we do is dictated by body chemistry – the action of hormones and neurotransmitters. We are all familiar with the feeling of being extremely alert, energetic and responsive when facing stressful, life-threatening situations. Normally, the same person who would find it difficult to even break into a jog, suddenly finds himself running at top speeds in life-threatening situations. You wonder what changed that in him. Was it the ferocious dog chasing or something inside him? In a way, it’s both. The flight or fight threat acts a stimulus and the body reacts appropriately, to deal with the situation. The reason is the secretion of adrenaline or epinephrine by the body as a response to stress and danger. The flight or fight response of the body to situations that threaten our very existence is aided internally by this hormone. It literally prepares your body for war, by activating all the basic instincts of survival in humans.
The hormone enhances production of energy in the body, activates all the sensory processes to full alert as a priority and slows down less important processes like digestion. The hormone leads to increase in blood sugar levels, higher heart rate and increase in blood pressure, while also kickstarting energy production. In short, it drives the body to optimum levels of energy and concentration in order to achieve one purpose – survival.
Effects of Endemic Epinephrine Production
Epinephrine acts as a hormone as well as neurotransmitter. It was simultaneously discovered by Japanese chemist duo of Jokichi Takamine and Keizo Uenaka in 1900. Later, Takamine successfully extracted and isolated it from the adrenal glands of sheep and oxen. Its artificial synthesis by Henry Drysdale Dakin and Friedrich Stolz in 1904 made its widespread usage today as a lifesaving drug possible.
The normal epinephrine levels in the human body are about 10 ng/L (nanograms per liter), which may be raised up to 50 times this level, when need be. This hormone is like the trigger for the activation of a war machine in the body. Once epinephrine is secreted in the adrenal gland and the nervous system, it flows in the blood stream reaching various organ centers. The hormone starts its operation by activating some strategically placed receptors in the body. One by one, it activates the α and β (adrenergic) receptors which are again trigger buttons for initiating many chain reaction processes.
Triggers Glucose Production From Glycogen
When epinephrine reaches the liver cells, it activates an α receptor there, which initializes a chain reaction, that culminates into breaking down of glycogen, releasing glucose, the energy packets of the body, into the blood stream (known as glycogenolysis). Simultaneously, it also activates the liver β receptors which again accelerates glucose production. The hormone also triggers glycogenolysis in the muscles.
Widens Arteries to Increase Blood Flow
β receptors are also present in muscles. When activated by epinephrine, they cause the widening of blood vessels, so that more blood can reach the muscles for efficient operation. The β receptor trigger also causes an increase in the heart pumping rate.
Narrows Arteries For Energy Conservation
On the other hand, the α receptors in muscles, when switched on by epinephrine, cause the narrowing or constriction of smooth muscles, resulting in decreased blood supply in some parts and increases resistance to blood flow in the arteries. This makes the skin pale, as less and less blood reaches it. This measure achieves conservation of body warmth. This is how naturally produced adrenaline or epinephrine revs up the body engine, for high performance.
Reduces Insulin Secretion
Epinephrine also causes the pancreas to substantially reduce the production of insulin, thereby creating an abundance of glucose in the blood, required for immediate energy production. This also makes the usage of fat as an energy source possible, which is normally inhibited by insulin.
Triggers Lipolysis in Adipose Tissue
The hormone further triggers the production of fatty acids for energy production from the breakdown of lipids in the adipose tissues. Along with glycolysis, this provides an abundance of raw material for energy production throughout the body.
Increased Heart and Respiratory Rate
Overall blood pumping volume and respiration rate also increases as an impact of this hormone, completing its primary objective of preparing the body to deal with high risk contingencies.
Epinephrine Shot Effects
Epinephrine can be artificially synthesized and is used as a drug for treating terminal conditions like cardiac arrest and other cardiac abnormalities. A shot of epinephrine injected in a patient who is going into cardiac arrest, constricts the blood vessels in other muscles, diverting more blood flow towards the heart and blood pumping rate increases. This is achieved due to the α and β receptor response to endorphin. This revival works but it also creates hyperactivity of the heart, which must be taken care of, by other means.
While epinephrine prepares the body for high performance, it indirectly weakens the immune system. This property is also used in the treatment of Anaphylaxis which is a severe response of the body to any kind of allergic object invasion.
Epinephrine shot weakens the otherwise severe immune response, making life easier for the victim. Asthmatic patients are administered shots of epinephrine which opens up the lung airways making breathing easier. Some of the side effects of getting injected with adrenaline shots can be headaches, tachycardia, hypertension, palpitations, tremors and pulmonary edema.
Thus epinephrine or adrenaline as it is popularly known, is the power booster of the body. It ensures energy supply and grants sharper instincts to help the body in dealing with crisis situations effectively.
Disclaimer: This article is intended to serve as a reference and should not be considered to be an alternative to advice from a certified medical practitioner.