Basic Functions of the Adrenal Gland
Corticosteroids
All different steroid hormones are based on cholesterol, with corticosteroids being based on Sterane
(cyclopentanoperhydrophenanthrene). Therefore, if you compare all three structures you can see
clear similarities
Cholesterol cyclopentanoperhydrophenanthrene Cortisol
Because of their cholesterol origin, they are also lipid soluble and pass through membrane with ease.
For this reason, these hormones aren't stored and secreted when required but rather produced in
proportion to demand. Once inside the cell they bind to intracellular receptors and alter gene
transcription directly or indirectly. Of course, the exact action of each hormone is reliant on its
structure, ability to recruit cofactors and specific receptors it binds to. For example, cortisol binds to
the complimentary glucocorticoid receptor in the cytosol, is translocated to the nucleus by
combining with various HSP's and binds to the glucocorticoid response element with co-activators in
order to trigger transcription of a gene.
, Classification of steroids
There are three main derivatives-
Pregnane derivatives= 21 carbons= Androstane derivatives= 19 Estrane derivatives= 18
Progesterone corticoids carbons= Androgens carbons= Oestrogens
Corticosteroids
All different steroid hormones are based on cholesterol, with corticosteroids being based on Sterane
(cyclopentanoperhydrophenanthrene). Therefore, if you compare all three structures you can see
clear similarities
Cholesterol cyclopentanoperhydrophenanthrene Cortisol
Because of their cholesterol origin, they are also lipid soluble and pass through membrane with ease.
For this reason, these hormones aren't stored and secreted when required but rather produced in
proportion to demand. Once inside the cell they bind to intracellular receptors and alter gene
transcription directly or indirectly. Of course, the exact action of each hormone is reliant on its
structure, ability to recruit cofactors and specific receptors it binds to. For example, cortisol binds to
the complimentary glucocorticoid receptor in the cytosol, is translocated to the nucleus by
combining with various HSP's and binds to the glucocorticoid response element with co-activators in
order to trigger transcription of a gene.
, Classification of steroids
There are three main derivatives-
Pregnane derivatives= 21 carbons= Androstane derivatives= 19 Estrane derivatives= 18
Progesterone corticoids carbons= Androgens carbons= Oestrogens
