Adrenocortical steroids structure

AG), a first-generation type 2 aromatase inhibitor (At), was originally developed as an anticonvulsant but was subsequently found to inhibit the synthesis of adrenocortical steroids. AG is a nonspecific, weak At, administered as a 250-mg dose four times daily with hydrocortisone supplementation because of unwanted adrenal suppression. Because of significant toxicities related to its anticonvulsant structure and its relatively weak inhibition of aromatase, its use has declined considerably with the advent of newer AIs. 

Compounds with steroid structures, such as adrenocortical hormones, sex hormones, cholesterol and bile acids, occupy a central position... 

Some of the most important physiological steroids are the adrenocortical hormones, synthesized by the adrenal cortex. Most of these hormones have either a carbonyl group or a hydroxyl group at Cl 1 of the steroid skeleton. The principal adrenocortical hormone is cortisol, used for the treatment of inflammatory diseases of the skin (psoriasis), the joints (rheumatoid arthritis), and the lungs (asthma). Figure 25-10 compares the structure of natural cortisol with two synthetic corticoids fluocinolone acetonide, a fluori-nated synthetic hormone that is more potent than cortisol for treating skin inflammation and beclomethasone, a chlorinated synthetic hormone that is more potent than cortisol for treating asthma. 

The rate of absorption is influenced by the status of the skin, chemical structure of the steroid and such other factors as formulation and formulation vehicle. Topical corticoids applied to diseased skin will be absorbed to some degree into the systemic circulation. When administration is chronic or when large areas of skin are involved, the absorption may be sufficient to cause systemic effects including cushinoid changes and adrenocortical suppression. 

The word hormone comes from the Greek to arouse or to excite. Hormones are chemical messengers that serve as a communication system from one part of the body to another. The steroid hormones, which include the sex hormones and the adrenocortical hormones, are closely related in structure to cholesterol and depend on cholesterol for their synthesis. 

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