1. Jenna Booth, Christa Beveridge, Abigail Ruths, and Paula Cook
Steroid Hormones
Jenna Booth, Christa Beveridge, Abigail Ruths, and Paula Cook

2. 13.10 Physiological Roles of Steroid Hormones

3. Cholesterol is the starting material for the synthesis of steroid hormones
The alphatic side chain on the D ring is shortened with the removal of a six- carbon unit
Results in progesterone

4. Progesterone
Starting compound for
Sex hormones
Adrenocorticoid

5. Adrenocorticoid Hormones
Products of adrenal glands
Two groups
Mineralocorticoids
Regulate the concentrations of ions
Glucocorticoids
Control carbohydrate metabolism
Corticoid-indicates that the site of the secretion is cortrex of the gland

6. Aldesterone is the most important Increased secretion
Mineralocorticoids
Aldesterone is the most important
Increased secretion
Enhances the reabsorption
Increases loss of K
Controls tissue swelling

7. Cortisol is major glucocorticoids
Glucorticoids
Cortisol is major glucocorticoids
Job is to increase the glucose and glycogen in the body
Fatty acid from fat storage cells and amino acids from body protiens to the liver
Antiinflamitory
Used to treat inflamatory diseases

8. Sex hormones
Male hormone-testosterone
Promotes normal growth of the male genital organ is synthesized in the testes from cholesterol
Female sex hormones
- most important is estradiol
-regulates mensral cycle
-level of estradiol increase when cycle begins

9. Continued…
LH (luteinizing Hormone)is another
Triggers ovulation
The ovulation increases progesterone level

10. Mifepristone blocks the action of progesterone
This is done by binding to the same receptor
Completely different approach is the morning pill
It has a progesertone-like compound called levonogestestrel

11. 13.11 Bile Salts

12. Products of cholesterol in oxidation
Cholesterol Trihydroxy derivative
End of aliphatic chain Carboxylic acid
Forms amide bond with amino acid (glycine or taurine)
Taurine has developed an importance in sports drinks
Ex) Red Bull contains sugars, caffeine and B vitamins as well as taurine

13. Bile salts are powerful detergents
One end is hydrophilic
Because of negative charge
The rest is hydrophobic
They can disperse dietary lipids in the small intestine into fine emulsions
Facilitates digestion
Similar to action of soap on dirt

14. Can also remove excess cholesterol in 2 ways
Breakdown cholesterol by themselves
Cholesterol is thus eliminated with bile salts
Solubilize deposited cholesterol in the form of bile salt- cholesterol particles

15. 13.12- Prostaglandins, Thromboxanes, & Leukotrienes

16. Prostaglandins Prostaglandins: group of fatty-acid-like substances
Seminal gland secretes 0.1 mg of prostaglandin per day
Small amounts present throughout body of both sexes
Synthesized in body from arachidonic acid by a ring closure at carbons 8 & 12
Enzyme catalyzing this reaction is cyclooxygenase (COX)
Product known as PGG2

17. Prostaglandins cont’d
Prostaglandin E group (PGE) has a carbonyl group at carbon 9
Subscript indicates # of double bonds in hydrocarbon chain
Prostaglandin F group (PGF) has two hydroxyl groups on the ring at carbons 9 & 11
Other prostaglandins (PGAs and PGBs) are derived from PGE
*diagram on page 294*

18. Prostaglandins cont’d
COX enzyme has 2 forms in body: COX-1 and COX-2
COX-1: catalyzes normal physiological production of prostaglandins
Lowers blood pressure, treats asthma, decongestant
COX-2: responsible for production of prostaglandins in inflammation
Helps to produce new tissue in injuries such as: heart attack, rheumatic arthritis, & ulcerative colitis
*aspirin inhibits both COX enzymes*

19. Thromboxanes = another class of archidonic acid derivatives
Synthesis also includes a ring closure
Derived from PGH2, but ring is a cyclic acetal

20. Blood Clots
Thromboxane  induces platelet aggregation
When blood vessel is ruptured, first line of defense is the platelets circulating in the blood. Forms an incipient clot
Thromboxane A2 causes other platelets to clump, increases clot

21. Blood Thinners
Aspirin and similar anti-inflammatory agents inhibit the COX enzyme
As a result, PGH2 and thromboxane synthesis is inhibited, and blood clotting is impaired
Many physicians recommend 81 mg aspirin a day for people at risk of heart attack or stroke
Forbid patients to use it before planned surgery  aspirin and other NSAIDs may cause excessive bleeding

22. PGH2
Thrombaxane A2

23. Variety of NSAIDs can inhibit COZ enzymes
Ibuprofin & indometacin (powerful painkillers) block aspirin’s effect
Eliminate anticlotting benefits
Use together is NOT recommended
Acetaminophen & diclophenac DON’T interfere, can be taken together

24. Leukotriens
Also act to mediate hormonal responses
Derived (like prostaglandins) from arachidonic acid by an oxidative mechanism
No ring closure

25. Leukotrienes occur mainly in white bloodcells
Also found in other body tissues
Produce long-lasting muscle contractions, especially in lungs
Can cause asthma-like attacks
Prostaglandins and leukotrines cause inflammation and fever

26. To counteract the effects of leukotrienes: Inhibit their uptake by Leukotriene receptors (LTRs) in the body Zafirlukast and Zileuton  commercial drugs used to treat and control athsma