Throwing Light on the Steroids Mechanism of Action
The secretions of endocrine glands, the hormones are specialized molecules which have a profound effect on our body and its functioning. Released into the blood, these molecules elicit specific responses from specific cells and impact our growth and development.
There are broadly two types of hormones released in our body. One is lipid soluble and the other is water soluble.
The hormone that would be in focus here is steroids! Read on:
What are steroid hormones?
A derivative of cholesterol and non-soluble in water, steroid hormones are excreted by adrenal glands, ovaries and testes. Impacting a wide range of physiologic functions, these are lipid-soluble and their action affects the gene expression. The steroid hormones produced by the adrenal glands are called aldosterone, cortisol and androgens. The male and the female gonads excrete the sex steroid hormone i.e. androgens, estrogens and progesterone.
Today, these hormones can also be synthetically produced.
Mechanism of action of steroids
Steroids mechanism of action
is quite unique. Unlike non-steroid or water-soluble hormones, the steroid
hormones are lipid soluble and thus can easily pass through the cell membrane of the target cell and cause changes within the cell itself. Since the cell membranes are composed of phospholipids bilayer; it allows the fat soluble molecules to diffuse into the cell but blocks the fat-insoluble molecules from diffusing inside.
Post diffusing inside the cell, these hormones are easily able to bind themselves to high-affinity receptors which are highly specific and present exclusively in the cytoplasm of the target cells. These receptors have a Hormone binding’ domain, a DNA binding’ domain and an amino terminal’. It is this terminal which interacts with other transcription factors to cause binding and expose the DNA binding zone. Once bonding between receptor and steroid has completed, the unified hormone-receptor complex gravitates towards the nucleus of the cell, enters it and dimerizes.
The resultant hormone-receptor dimmers now bind themselves with another
specific receptor, present in the chromatin and referred to as Hormone
(Steroid) Receptor Elements (SREs or HREs) of DNA. This process of binding is referred to as DNA transcription and the resultant formed product is called the mRNA. These formed mRNA molecules undergo change by a process of translation and produce two new proteins. The new proteins so formed now go ahead and manifest the physiological
action of the hormones. These proteins are also used to build muscles in our
Anabolic steroids and Legal steroids
As already stated, these steroid hormones could be synthetically manufactured which functioned similarly and accelerated
the muscle production in our body. However, soon their dangerous side effects were also manifested and verified. The danger level was so high that many countries had to legally ban the usage of these anabolic hormones. To mitigate the harmful effects but get the same desired result of muscle building, harmful substance used in making synthetic steroids like Oxymethalone, Dianabol, Trenbolone etc. were dumped and natural and herbal substitutes like vitamins, herbal boosters and prohormones were used. With legal steroids, sometimes the same results were obtained but the harmful effects were successfully eliminated.