Topic 81 - Synthesis, regulation and physiological effects of glucocorticoids

Question 1

Words to include

Answer 1

• Glucocorticoids
  
  • Cortisol
  • Corticosterone
• Adrenal cortex
  
  • Zona glomerulosa / zona arcuata
    
    • ​Mineralocorticoids (aldosterone)
  • Zona fasciculata
    
    • Glucocorticoids
  • Zona reticularis
    
    • Androgens
    • Estrogens
  • Adrenal medulla
    
    • Catecholamines
• Steroids
• Regulation
  
  • Hypothalamic - pituitary (CRF-ACTH) control
  • Long feedback loop
  • Anterior lobe of pituitary
  • Hypthalamus
  • ACTH stimulation
• Effects
  
  • Energy reserves
  • Metabolism
    
    • Carbohydrate metabolism
      
      • Hyperglycemia
      • Glyconeogenesis (GNG)
        
        • Amio acid
        • Liver
        • Diabets
        • Antiinsulin effect
    • Protein metabolism
      
      • Protein catabolism
      • Protein synthesis
      • Nitrogen balance (÷)
      • Free amino acids
    • Lipid metabolism
      
      • Cleaving
      • Redistribution
      • Lipolysis
      • Free fatty acids (FFA’s)
  • Circulatory
  • Bloo cell, lymphoid
  • Nervous system
  • Glucocorticoid isufficiency
    
    • Na⁺ loss
    • Oligemia
    • K⁺ increase (cardiac weakness)
    • Edema in capillaries
    • Muscular weakness

Question 2

Topics to include in the essay

Answer 2

1. General about the adrenal cortex
2. Regulation of glucocorticoids
3. Effects of glucocorticoids

Question 3

Where are the glucocorticoids produced?

Answer 3

• Adrenal cortex in:
  
  • Zona fasciculata
  • Zona reticularis

Question 4

Which group of hormones does glucocorticoids belong to?

Answer 4

Steroids

Question 5

General about the adrenal cortex

Answer 5

• There are three zones of the adrenal cortex:
  
  1. Zona glomerulosa / zona arcuata
  2. Zona fasciculata
  3. Zona reticularis
• Hormones of the adrenal cortex:
  
  • Mineralocorticoids (aldosterone)
    
    • Produced in zona glomerulosa
  • Glucocorticoids (cortisol, corticosterone)
    
    • Produced in zona fasciculata and zona reticularis

Question 6

Regulation of glucocorticoids

Answer 6

• Hypothalamic – pituitary (CRF – ACTH) control is the basis of the regulation
• The production in the zona reticularis is less dependent on the ACTH
• The roles of the glucocorticoids are determined by the long feedback loop

Question 7

Name the most prominent glucocorticoids

Answer 7

• Cortisol
• Corticosterone
• Ru, Ca: these hormones occur in equal concentration
• Sheep, sus, human: cortisol is the important glucocorticoid

Question 8

Physological effects of glucocorticoids

Answer 8

• Physological effect
  
  • Long lasting mobilization of the energy reserves of the body

1. Carbohydrate metabolism
2. Protein metabolism
3. Lipid metabolism
4. Circulatory effect
5. Blood cells, lymphoids
6. Neural effects

Question 9

Physological effects of glucocorticoids

Carbohydrate metabolism

Answer 9

• Guconeogenesis (GNG):
  
  • Amino acids are transported to the liver for intake
  • Amino acid mobilization increases
  • GNG is excessive → steroid diabetes develops
  • Metasteroid diabetes
  • Antiinsulin effect of glucocorticoids
• Hyperglycemia

Question 10

Physological effects of glucocorticoids

Protein metabolism

Answer 10

• Protein catabolism
• Glucocorticoids decrease protein synthesis and increase protein cleaving
  
  • Nitrogen balance becomes negative
  • Enough free amino acids for GNG

Question 11

Physological effects of glucocorticoids

Lipid metabolism

Answer 11

• Glucocorticoids increas:
  
  • Lipolysis
  • Plasma level of free fatty acids
  • Extent of fat burning
• Cleaving of fats
• Redistribution

Question 12

Physological effects of glucocorticoids

Circulatory effects

Answer 12

• Glucocorticoid insufficiency:
  
  • Na⁺ loss, oligemia
  • K⁺ increase: cardiac weakness
  • Increased capillary permability: edema
  • No permissive effect: muscular weakness
  • Water-poisoning

Question 13

Physological effects of glucocorticoids

Blood cells, lymphoids

Answer 13

• AC overproduction:
  
  • Eosinophil and basophil granulocytes decrease
  • Lymphoid tissue degrades
• AC extirpation:
  
  • Lyphoid hyperplasia

Question 14

Physological effects of glucocorticoids

Nervous system

Answer 14

• AC hyperfunction:
  
  • Convulsive susceptibility increases
• AC extirpation:
  
  • Depression
  • Psychic disorders