The mechanism of steroid powders -- gene expression theory

The relative molecular weight of steroid powders is small (only about 300) and fat soluble, so it can enter the cell through the cell membrane. After entering the cell, it plays a biological role by affecting gene expression in two steps.

The first step is the combination of hormone and cytoplasmic receptor to form hormone receptor complex.

After the receptor binds to the hormone, its configuration changes, so that the hormone receptor complex in the cytoplasm has the ability to penetrate the nuclear membrane.

The second step is to bind the hormone receptor complex to the non histone specific site of chromatin after entering the nucleus, start or inhibit the DNA transcription process of this part, and then promote or inhibit the formation of mRNA.

The result is to induce or reduce the synthesis of certain proteins (mainly enzymes) and cause corresponding biological effects, as shown in the figure below. Like nitrogen-containing hormones, these hormones also act in a series of chain reactions, and the effect is amplified step by step, so they also reflect the characteristics of high efficiency.

In addition to the above modes of action, steroid powders can also act directly on the lipid components of the cell membrane by changing the structure of the membrane; When the number of steroids is small, although they do not show their unique role, they are good conditions for the role of other hormones to play the so-called "permissive role", which can not be explained by gene expression theory.

Why are steroid powders so important?

Steroid powders are a kind of organic compounds widely distributed in the biological world. One of its most important classifications is steroid hormones.

Steroid powders can transmit chemical information in organisms. They have a wide variety and play an important role in maintaining life.

The first is glucocorticoids, which are produced in the adrenal gland above the kidney and affect the cells of the whole body.

Glucocorticoids can reduce inflammation and control blood glucose and metabolism; The second category is mineralocorticoids, the most important of which is aldosterone.

Mineralocorticoid is also produced in the adrenal gland. It can send information to the kidney to control the balance of water and electrolyte in the human body.

Without aldosterone, the content of water and sodium ions in the human body will decrease, and the content of potassium ions will increase. This imbalance will affect the heart;

The third category is androgen, that is, male sex hormone, which will bring hair growth and change vocal cords, bones, muscles and reproductive organs; The fourth and fifth categories are estrogen and progesterone, that is, female sex hormones, which are produced by the ovary and act together with the hormones produced by the pituitary gland to control the menstrual cycle.