Mechanism of Hormone Action

1
Mechanism of Hormone Action
Biological Function
2
Hormone Structure and Function
Hormone Definition

• Chemical substance
• Secreted by specific cells
• Directed into the circulation
• Acts at a distance
• Acts on target cells that have specific means
  
• to receive the signal
• Regulates some function(s) of the target cells
• Generally found in very low concentration

3
Hormone Structure and Function
Is a hormone the message or the messenger?
4
Hormone Structure and Function
How can hormones serve as the message?
Insulin
Message
5
Hormone Structure and Function
What are the different classes of hormones?
Two basic classes Amino Acid Lipid
Amino Acid Petides, proteins, AA derivatives
Lipid Sterols, steroids, and fatty acids
6
Amino Acid Derivatives
Amino Acids
7
Peptides and Proteins
8
Amino Acid Derivatives
9
(No Transcript)
10
Lipid Derivatives
11
Sterol Derivatives
Cholesterol
Vitamin D
12
Fatty Acid Derivatives
Prostaglandins
13
Hormone Structure and Function
How can hormones serve as the message?
How can hormones serve as the messenger?
14
Episodic Hormone Secretion Pulses
Frequency and Amplitude
Messenger
15
Mechanism of Hormone Action
What makes a target cell a target?
16
Hydrophyllic Hormones
17
Hydrophyllic Hormones
Variety of signaling pathways
18
Hydrophobic Hormones
19
Mechanism of Hormone Action
Acute and Chronic Effects