Hormones

Hormones are complex and essential chemicals that play a significant role in regulating various bodily functions. They act as messengers that send signals to different organs and tissues, affecting their growth and development, metabolism, mood and more.

The most mysterious compounds

Doesn’t everything about hormones seems like the best kept secret??? It’s like the most mysterious compounds in our bodies whose complete function doesn’t want to be revealed. We’re still finding out a lot about them and they are the subject of many researches still.

What is characteristic of hormones is that they are efficient in very low concentrations and are usually produced in one part of the body and used to influence what occurs in some other body part. They travel through our bloodstream, or short distances among cells. Those low concentrations also make their isolation and identification more difficult.

Where are they produced?

Hormones are mostly produced in endocrine glands – hypothalamus, pituitary, pancreas, adrenal, liver, testes, and ovaries. Pituitary gland mostly does cause other glands to produce hormones that affect other systems. Our endocrine system is so magnificent because it is spread all over our bodies and consists of a number of apparently unrelated organs – liver, ovaries, testes, pancreas, thyroid and other glands and malfunction of one affects all other ones. All for one, one for all – can be easily used for this complex network.

The hormonal structure

The hormones structure can be as:

proteins,
steroids or
amines.

Protein ones are polypeptides produced by the pituitary and hypothalamus glands. This group includes well-known insulin. Important protein hormones are thyrotropin and growth hormone, which with their releasing factors provide a mechanism to start and stop actions, such as the biochemical process of growth.

The steroid ones are mainly cholesterol derivatives and are produced in ovaries, testes and adrenal glands. Cool if you’ve guessed them, if not, that are estrogen, androgen, responsible for the development of sex characteristics in humans, and cortisol that’s responsible for our stress response.

The amine group is mainly derivatives of the amino acid tyrosine and they are produced in the thyroid and adrenal glands. Thyroxine made in the thyroid gland is one of the most important substances in our bodies because it influences the carbs metabolism and protein synthesis and is also involved in cardiovascular and brain function. Adrenal glands are making epinephrine and norepinephrine which control blood flow and heart rate.

Prohormones and enzymes

One similarity of hormones with enzymes is that they are mostly present in their inactive form, as prohormones, which our body has cleverly figured out so it can store large amounts of dormant molecules for quick activation if needed.

You need the quickest reaction of insulin you can get when you eat that exploding hot chocolate lava cake, because too much insulin in the system leads to low blood sugar, and insufficient amounts to high blood sugar. Both states are critical to our health, so the storage of proinsulin that can activate and transform into insulin almost immediately is the solution for the balanced blood sugar level that we need.

The prohormone feature is also important for the regulation of blood pressure. Activated angiotensin (causes blood vessels constriction which increases blood pressure) signals the cortex of adrenal glands to release aldosterone (increases sodium retention and release of potassium which also tends to increase blood pressure). Too much of these two hormones and you get hypertension.

Two hormonal functions

Hormones function in two models – one is called second-messenger (protein and amino hormones) and the second steroid action. In the first one, a hormone binds to a receptor site on a cell’s exterior which induces the release of another substance in the cell that causes the desired result (like epinephrine (adrenalin) that binds to the outside of the liver cell and induces the production of specific enzyme and synthesis of the substance called cAMP which is the second messenger that induces the series of chemical reactions that leads to the breakdown of glycogen and its transformation to glucose).

cAMP actions — *Actions of cAMP within target cell (credit: sciencedirect.com)*

In the steroid action case, those hormones get directly into the cell through the membrane’s lipid bilayer because they are lipophilic in their nature. Such hormone is estradiol, an estrogen type, that gets directly into the cell and binds to the receptor protein, changing its shape which allows it to access the cell’s nucleus and bind to chromosomes. That stimulates the production of mRNA which is responsible for carrying information outside the cell and the synthesis of protein molecules through translation.

Conclusion

Whew, I tried to keep it as simple as possible 🙂 But those guys are so complex and we should be thankful to them for carrying such a burden for our bodies to function properly.

It is important to note that while hormones play an essential role in the body, they can also have negative effects if their levels are imbalanced. Therefore, it is crucial to maintain a healthy diet and lifestyle to promote hormone balance. Exercise, stress management, and getting enough sleep are all essential for hormone regulation.

In conclusion, hormones are essential chemicals that play a critical role in regulating bodily functions. They are produced by various endocrine glands located throughout the body and are released into the bloodstream to reach their target cells. While hormones such as insulin, cortisol, testosterone, estrogen, and progesterone are all essential for health, imbalances can lead to a range of health problems. Therefore, it is crucial to maintain a healthy diet and lifestyle to promote hormone balance and prevent health issues.