1. Steroid Hormones
Cholesterol
Starting material

2. Steroid Sex Hormones Androgens: male sex hormones
synthesized in the testes
responsible for the development of male secondary sex characteristics

3. Steroid Hormones Among the synthetic anabolic steroids are:
Prohormones, see p Chemical Connections 20G
Why are these hormones of interest?
Do steroids really work? i.e. improve muscle mass
and performance? . . .

4. A resounding Yes . . .

5. Steroid Sex Hormones Estrogens: female sex hormones
synthesized in the ovaries from progesterone  testosterone (aromatization) estradiol
responsible for the development of female secondary sex characteristics and control of the menstrual cycle

6. Steroid Sex Hormones
A woman's monthly cycle w/o the pill (Blue and Red solid lines)
A woman's monthly cycle on the pill (Blue and Red dashed lines)
Progesterone-like analogs are used in oral contraceptives:
they Make the body think it is Pregnant at all times. . .
 preventing folicle stimulation and ovulation. . .

7. Steady stream of Progesterone required for implantation
and development of oocyte
Other pills block Progesterone
all together. . .e.g. RU- 486
Progesterone
Prevents egg from
staying implanted . .
Gets released. . .

8. Steroid Hormones Adrenocorticoid hormones
synthesized in the adrenal cortex.
regulate metabolism of carbohydrates.
decrease inflammation.
involved in the reaction to stress.

9. Bile Salts Bile salts, the oxidation products of cholesterol.
synthesized in the liver, stored in the gallbladder, and secreted into the intestine where they emulsify dietary fats and aid in their absorption and digestion

10. Other Classes Lipids: - Prostaglandins - Thromboxanes - Leukotrienes
Prostaglandins: a family of compounds that have the 20-carbon skeleton of prostanoic acid.

11. Prostaglandins
Not stored in tissues - synthesized from membrane-bound 20-carbon polyunsaturated fatty acids in response to specific physiological triggers.
One such polyunsaturated fatty acid is arachidonic acid.

12. Prostaglandins

13. COX Enzymes The COX (cyclooxygenase) enzyme occurs in two forms:
1. COX-1 catalyzes the normal physiological production of prostaglandins.
2. COX-2 is responsible for the production of prostaglandins in inflammation.
Tissue is injured or damaged, special inflammatory cells invade the injured tissue and interact with resident cells, e.g. smooth muscle cells or skin.
This interaction activates COX-2
and prostaglandins are synthesized.
Aspirin helps relieve this anti-inflammatory response
By inhibiting the production of prostaglandins . . .

14. Thromboxanes Thromboxanes are also derived from arachidonic acid.
Thromboxane A2 induces platelet aggregation and vasoconstriction.
Aspirin and other NSAIDs inhibit the synthesis of thromboxanes by inhibiting the COX enzyme.

15. Challenge Questions How Does Aspirin prevent strokes
caused by blood clots in the brain?
NOTE: Doctors recommend 81mg/ day for people at risk
for Heart Attack or stroke. . .

16. Leukotrienes Leukotrienes are also synthesized from arachidonic acid.
They occur mainly in leukocytes.
They produce muscle contractions, especially in the lungs and thereby can cause asthma-like attacks.
In this regard, they are 100 times more potent than histamine.
Several recently-developed anti-asthma drugs inhibit the synthesis of leukotrienes.