Steroid
hormone is a steroid that acts as a hormone.
They
are grouped on the basis of the receptors they bind.
vGlucocorticoids
vMineralocorticoids,
vProgesterone
vAndrogens
vEstrogens
•The
natural steroid hormones are generally synthesized from cholesterol in the
gonads and adrenal glands.
•
These forms of hormones are lipids.
•They
can pass through the cell membrane as
they are fat-soluble, and then bind to steroid hormone receptors which may be
nuclear or cytosolic
depending on the steroid hormone, to bring about changes within the cell.
•Steroid
hormones are generally carried in the blood bound to specific carrier proteins
such as SHBPs and CHBPs.
•Further
conversions and catabolism occurs in the liver, in other "peripheral"
tissues, and in the target tissues.
•A
variety of synthetic steroids and sterols have also been contrived.
•Most
are steroids, but some non-steroidal molecules can interact with the steroid
receptors because of a similarity of shape.
•Some
synthetic steroids are weaker, and some much stronger, than the natural
steroids whose receptors they activate.
Examples
Of Synthetic Steroids
ØGlucocorticoids: alclometasone, prednisone,dexamethasone,
ØMineralocorticoid: fludrocortisone
ØVitamin
D: dihydrotachysterol
ØAndrogens: apoptone, oxandrolone, oxabolone, testosterone, nandrolone
(also known as anabolic steroids)
ØEstrogens:
diethylstilbestrol (DES)
ØProgestins: danazol, norethindrone, medroxyprogesterone acetate, 17-Hydroxyprogesterone caproate.
Some
steroid antagonists:
ØAndrogen:
cyproterone
acetate
ØProgestins: mifepristone, gestrinon
