Hormones – Know our body to learn to master it better

Hormones – Our body is a single whole of cells that work in harmony and coordination with each other thanks to the intensive exchange of information that flows constantly between them – the so-called. cellular signaling. Hormones are one of the types of signaling molecules that are released from a cell and act at different distances from it.

Types of cellular signaling


Depending on this distance, the signaling in our body is of three main types:

  • Endocrine – here signaling molecules, called hormones, act on a target cell that is far from the site of their synthesis – the endocrine glands. It is very important to note that hormones are synthesized in extremely low amounts in the body, but their effect is huge. In animals and humans, hormones are usually transported from the site of their synthesis to their target cell through the blood.

  • Paracrine – here signaling molecules synthesized by a single cell affect only the cells that are in close proximity. Conducting a nerve impulse from one nerve cell to another or from a nerve to a muscle cell (to provoke or stop muscle contraction) by signal neurotransmitters is a typical example of paracrine signaling.

  • Autocrine – in this type of signaling, cells respond to signaling molecules that are synthesized by themselves, that is, they are targets of themselves. Many so-called growth factors that push the cell to grow and divide are such signaling molecules. This type of signaling is especially common in cancer (tumor cells), many of which have overproduction and release of growth factors that affect neighboring non-tumor cells and thus turn them into cancer.

 

Signal capture mechanism

In order for a signaling molecule to act on its target cell, that cell must have a specific receptor for the molecule. Receptors are usually located on the surface of the cell-cell membrane, but a large part are also intracellular. The binding of the signaling molecule to its receptor causes complex spatial changes in the formed complex and these changes trigger a whole sequence of reactions (starting with a change in the amount of so-called secondary signaling molecules in the cell, eg cyclic adenosine monophosphate), which lead to adequate response from the cell to the received signal.

Types of hormones

Most hormones fall into one of three broad categories:

  • Small fat-soluble molecules that cross the cell membrane and interact with intracellular receptors;
  • Water-soluble molecules;
  • Fat-soluble molecules that interact with surface cell receptors.

Small fat-soluble hormones with intracellular receptors

Many fat-soluble hormones cross the cell membrane and interact with receptors located in the cytoplasm or cell nucleus. The resulting complexes, after passing into the nucleus (where there is DNA) bind to areas of DNA that regulate the synthesis of certain cellular products, such as proteins.

Hormones of this type include steroids (eg cortisol, progesterone, estradiol and testosterone), thyroxine and retinoic acid. The starting compound from which all steroids are synthesized is cholesterol and therefore has a similar structure. The effect that steroids have can last for hours or days, and therefore they often affect the growth and development of certain tissues (eg muscle) – processes that are relatively slow from a biochemical point of view.

receptors stayfitlonger.com

 

Water-soluble hormones with surface cell receptors

Because water-soluble signaling molecules cannot cross the cell membrane, they attach to four major groups of receptors on the cell surface.

This large class of compounds consists of two groups:

  • Peptide hormones – such as insulin, growth factors and glucagon.

  • Small charged molecules – such as catecholamines (epinephrine, norepinephrine and dopamine) and histamine, which are derivatives of some amino acids. Most water-soluble hormones cause a change in the activity of one or more enzymes that are present in the target cell.

For this reason, the effect of them is extremely fast, but also short-lived. These hormones can also cause reversible changes in the amount of RNA and protein in the cell, but can also cause irreversible changes, such as cell differentiation.

Fat-soluble hormones with surface cell receptors

In the group of these hormones, prostaglandins are the most numerous – at least 16 different compounds from 9 chemical groups, which are part of a larger group called oicosan hormones. Oicosan hormones are synthesized from arachidonic acid – one of the essential Omega 6-polyunsaturated fatty acids, which we must provide from food. In addition, this group of hormones includes prostacyclins, thromboxanes and leukotrienes.

Signal conduction mechanism

As already mentioned, the binding of a hormone to a cell surface receptor results in a short-term increase or decrease in the concentration of intracellular molecules called secondary signaling molecules. These are 3,5-cyclic guanosine monophosphate, 3,5-cyclic adenosine monophosphate, 1,2-diacylglycerol, inositol 1,4,5-triphosphate, various inositol phospholipids and, of course, calcium Ca (2+).

 

The altered amount of one or more secondary signaling molecules gives impetus to a rapid change in the activity of one or more enzymes or non-enzymatic proteins (Fig. 2). The metabolic functions that are controlled by this altered enzyme activity are the breakdown and absorption of glucose, the accumulation and utilization of fats, and the excretion of cellular products.

reseptors stayfitlonger.com

 

Regulation of hormonal levels

As you may already be convinced, hormones can cause powerful changes in the body and therefore their synthesis, secretion from cells and destruction are subject to fine regulation by complex control biochemical networks. Control of hormone levels is carried out mainly in two ways – through the principles of positive and negative feedback. This regulation is especially important in coordinating the simultaneous action of many hormones in the processes of growth and development of the body.

Often hormone levels are mutually regulated – a change in the amount of one hormone leads to a change in the amounts of other hormones. Therefore, the introduction of hormones into the body (for example by injection), albeit in minimal amounts, can lead to catastrophic consequences if it is not performed under strict medical supervision and if it is not carried out after very precise tests.

People also look for :

Recovery – Perhaps The most Important and most underestimated training element

Do Your Muscles Have a Fever? how to treat it ?

Stretching and flexibility Training – Benefits

The Laughter The most efficient and easy way to Shut the door of Stress and Disease