QUESTIONS

1. Growth hormone is secreted by the (choose one) anterior/posterior pituitary gland (also known as the adeno/neuro hypophysis).
    
2. Growth hormone leads to the production of _______________ by the liver.  Many of the actions of growth hormone are mediated by this substance.
    
3. Another name for Growth hormone is _______________.
   
4. The release of Growth hormone from the pituitary gland  is regulated by _______________ & _______________ which reach the pituitary via (choose one) direct fibers from the hypothalamus/the hypothalamo-hypophyseal portal system.
    
5. Growth hormone's effect on protein is primary (choose one)  anabolism/catabolism. Free levels of amino acids increase/decrease under the influence of growth hormone.
    
6. Growth hormone (choose one) increases/decreases hepatic gluconeogeneiss and increases/decreases blood sugar level.
    
7. Growth hormone increases/decreases lipolysis.
    
8. Why don't acromegalic animals grow very big?
    
9. Classically (emphasis on classically)  which statements best fit canine acromegaly & which fit feline acromegaly?
   
   a) patient is male
   b) patient is intact female
   c) patient has been on megace
   d) patient is a diabetic not losing weight
   e)  patient has a thyroid nodule but is not hyperthyroid
   f)  patient has inspiratory stridor and is not brachycephalic
   g) prognosis usually good
   h) prognosis usually bad
    
10. If the patient is acromegalic due to an elevated progestin level and as treatment she is spayed, will her soft tissue abnormalities resolve?
     
11. How is acromegaly diagnosed in a hyperglycemic cat?
     
12. How is acromegaly diagnosed in a euglycemic cat?
     
13. How is acromegaly usually diagnosed in the dog?
     
14. What treatment options are available for acromegalic cats?
     
15. The usual cause of feline acromegaly is an acidophilic hypophyseal (choose one) adenoma/adenocarcinoma.  And what does "acidophilic" refer to?
    
    
    
    
     

ANSWERS

1. Growth hormone comes from the anterior pituitary which is also called the adenohypophysis.
   
   
   
   
    
2. Somatomedin C is produced by the liver & mediates some but not all of growth hormones actions.
   
   
   
   
    
3. Another name for growth hormone is  Somatotrophin (somatotropin without the "h" is also correct)
   
   
   
   
    
4. The release of GH is regulated by Somatostatin (which turns it off) & GNRH -also called  GNRF- (which turns it on).  Both visit the pituitary from the hypothalamus by way of they hypothalamo-hypophyseal portal system (which is how the hypothalamus talks to the ant. pit. - It uses direct fibers to talk to the post. pit.)
   
   
   
   
    
5. Growth hormone's effect is anabolism.  It decreases free amino acid levels in the blood.
   
   
   
   
    
6. Growth hormone increases hepatic gluconeogenesis & increases blood sugar level.
   
   
   
   
    
7. Growth hormone increases lipolysis.
   
   
   
   
    
8. Animals with acromegaly don't get big because their physeal plates are already closed.  There is, however, substantial soft tissue hypertrophy - increased distance between teeth, ridges on the skull, prominent lower jaw, and spondylosis deformans.  Bones which undergo membranous ossification rather than endochondral ossification can still respond to growth hormone (vertebrae, skull).
   
   
   
   
    
9. a) patient is male   - feline
   b) patient is intact female   - K9
   c) patient on megace - K9
   d) patient diabetic not losing wt - feline
   e) patient has a thyroid nodule but is not hyperthyroid -feline
   f) patient has insp. stridor - K9
   g) Px good - K9
   h) Px bad - feline
   
   
   
   
    
10. YES, soft tissue abnormalities resolve after removing progestin source.
    
    
    
    
     
11. In a hyperglycemic cat, a resting growth hormone level can be submitted.  Note this is a highly species specific assay so be sure the lab you use is using the test for the species you want.
    
    
    
    
     
12. In a euglycemic cat,  a resting growth hormone level is compared to one taken one hour after 1 mg/kg glucose is given PO or IV.  Gh should suppress to < 5 ngm/ml.  This test is not too surprisingly called a glucose suppression test.
    
    
    
    
     
13. In dogs, acromegaly is usually diagosed by a response after removal of a progesterone source.
    
    
    
    
     
14. Treatment options for cats aren't too good. There's surgery which hasn't been too successful.  There's radiotherapy. There's drugs (estrogens, bromcryptine, somatostatin analogs).  Nothing really works well.
    
    
    
    
     
15. The usual pituitary tumor is an adenoma.  The term "acidophilic" refers to a structure that readily stains with acid, such as the alpha cell of the adenohypophysis.