Classification of Adrenocortical Hormone

Translated By: Joe Hing Kwok Chu 朱興國编譯

Section 1: Classification of adrenocortical hormone

There are more than fifty kinds of steroids produced by the adrenal glands. Not all of them are secreted into the blood stream. The more important ones are those that exist in the veins of the adrenal glands and possess physiological functions. There are nine different kinds of steroid found in the veins of the adrenal glands. 

I. Classification by structures

According to their chemical structures, they can be classified into three categories:

1. steroid of having twenty-one -carbon atoms pregnehydroxy as basic structure: cortisol (hydrocortisone), 11-deoxycortisol, corticosterone, 11-deoxycorticosterone and aldosterone.

2.steroid of having nineteen carbon atoms male hydroxy as basic structure: dehydroepiandrosterone, delta4-androstenedione, and 11-hydroxy-delta4-hydroxyandrosterone.

3. steroid of having eighteen carbon atoms female hydroxy as basic structure: estrone and estradiol.

The table below describes the individual classifications:

II. Classification by  medical functions and the relationship of their structures:

1. Glucocorticoid

    Includes cortisol and corticosterone. Glucocorticoid moderates the metabolism of sugar, fat, and protein and can raise the resistance to the adverse stimulation of the body. Clinically applied steroids belong to this group, like cortisone, hydrocortisone, and their pharmaceutical derivatives: prednisone, dexamethasone etc. It is called glucocorticoid because of the early discovery of its function on the metabolism of sugar. In structure they possess the common characteristics of being able to affect physiological functions which beside require d4-21- 3,20-prednenolone- 21- sterol-3,20 diketone basic structure, and in site 11th possess oxygen  base (like hydroxy base of  hydrocortisone,  and acetone base of cortisone). If in site 17th, a replacement by α-hydroxy  as glucocorticoid the action will be much stronger than corticosterone.

Translator's note: In America sometimes glucocorticoid and cortisol are used interchangeably. Cortisol also has some mineralocorticoid effect of retaining sodium and excreting potassium. Although  the strength of cortisol and aldosterone in sodium retention is about 0.3:2,500; and the strength of potassium excretion is about 24:500, usually 200 times more cortisol than aldosterone is secreted. Therefore cortisol has an important overall influence on sodium retention. In fact, cortisol insufficiency is diagnosed clinically by using a water load challenge. A subject is given 1 L of water to drink. In a normal individual this load will be cleared in 1-2 hour, but not for at least 12 hours in those with cortisol insufficiency. 

2. Mineralocorticoid

    Mineralocorticoid inncludes aldosterone, 11-deoxycorticosterone, 11-deoxycortisol. Mineralocorticoid  helps the body to retain sodium and expel potassium. It is an essential hormone in maintaining the balance of electrolytes and body fluid. It also possess the d4-21- 3,20-prednenolone basic structure; but on the 11th position it lacks oxygen (like deoxycorticosterone and deoxycortisol), or on the 18th position it contain (-CHO) (like aldosterone). The 18th position of (-CHO) can obviously increase the mineralocorticoid effect; thus the retaining sodium effect of aldosterone is 25 times stronger than that of 11-deoxycorticosterone. But, if on the 17th position,a-CHO is added, the effect is weaker. Thus sodium retention effect of 11-deoxycortisol is only 3% of that of 11-deoxycorticosterone.

3. Sex Hormone

Sex hormone can be classified into 19 carbon androgen and 18 carbon estrogen

    a. androgen

    b. estrogen

Back to Adrenocortical Hormone

See Bio-chemistry dictionary.

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