Steroid Hormones
HO
Cholesterol
Starting material
Steroid Sex Hormones
• Androgens: male sex hormones
• synthesized in the testes
• responsible for the development of male secondary sex
characteristics
H3 C OH
H3 C
H3 C
O
H3 C
HO
Testosteron e
And rosterone
O
Steroid Hormones
• Among the synthetic anabolic steroids are:
Prohormones, see p.515
H3 C CH3
OH
H3 C
H3 C
H3 C
O
Chemical Connections 20G
OH
CH3
O
Me th an di en on e
Me th en ol on e
Why are these hormones of interest?
Do steroids really work? i.e. improve
muscle mass
and performance? . . .
H3 C O
H3 C
O
4-An droste n e-3,17-di on e
H3 C OH
A resounding Yes . . .
H3 C
O
H3 C
HO
Testosteron e
And roste
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
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. . .
•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. . .
Steroid Hormones
•
Adrenocorticoid hormones
•
•
•
•
synthesized in the adrenal cortex.
regulate metabolism of carbohydrates.
decrease inflammation.
involved in the reaction to stress.
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
H3 C
HO
CH3
H3 C
HO
CH3
NH
COO-
H3 C
HO
O
OH
Gl ycoch ol ate
(from glycin e)
H3 C
HO
OH
Tau roch ol ate
(from tau rin e)
O
NH
SO 3 2 -
Other Classes Lipids:
- Prostaglandins
- Thromboxanes
- Leukotrienes
• Prostaglandins: a family of compounds that have
the 20-carbon skeleton of prostanoic acid.
9
5
7
1
3
8
6
4
2
12
14
16
18
COOH
10
11
13
15
17
20
19
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.
9
11
8
12
6
14
5
15
Arachid on ic acid
COOH
Prostaglandins
9
COOH
11
15
Arach i don i c aci d
2 O2
O
O
As pirin an d oth e r
NS AIDs in h i bit
thi s e n z ym e
cycl ooxyge n as e (C O X)
9
COOH PGG
2
15
11
OOH
O
HO
9
9
COOH
11
HO
COOH
15
OH
PGE2
HO
11
15
OH
PGF2
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 . . .
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.
9
10
11
8
1
COOH
O
O
12
15
OH
Thromb oxan e A2
20
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. . .
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.
OH
OH
12
5
20
Leukotrien e B4
1
COOH