Anterior Pituitary Hormones (prolactin + GH) Flashcards
What class of hormone is prolactin?
Hydrophilic peptide hormone
What is prolactin’s target tissue?
Mammary Glands
What is prolactin’s functions?
Lactogenesis
Growth
Ovulation inhibition
What stimulates prolactin before or during pregnancy?
Estrogen and thyroid releasing hormone
(Puberty/pregnancy)
Dopamine inhibition
What stimulates prolactin primarily after pregnancy?
Lactation
Sleep
Dopamine antagonist
What inhibits prolactin?
Dopamine or dopamine agonists
D/C of stimuli
What class of hormone is Growth Hormone?
Hydrophilic peptide hormone
What is GH’s target tissue?
Liver
Adipose tissue
Muscle/other tissues
What is the function of GH?
Growth and metabolism
How does GH stimulate tissue growth?
GH stimulates the liver to release somatomedins which stimulates cellular proliferation
What is the other name for somatomedin?
Insulin-like growth factor 1
How and why does GH stimulate fat metabolism?
GH stimulates lipolysis to breakdown fat stores and free up glucose
How and why does GH stimulate glucose metabolism?
GH inhibits glucose uptake and stimulates liver glucogenolysis (breakdown of glycogen) to release glucose into the bloodstream
GH does this to maintain blood glucose levels during growth
How and why does GH stimulate protein?
GH stimulates uptake of protein into tissues to promote muscle building
What stimulates GH?
Growth Hormone Releasing Hormone
Puberty
Hypoglycemia
Exercise
Stage 4 Deep Sleep
Dietary protein
What inhibits GH?
Cortisol/glucocorticoids
Somatostatin (GHIH)
Hyperglycemia
Negative feedback loops
What is a cortisol syndrome that can inhibit GH?
Cushing’s syndrome
Why does cortisol inhibit GH?
Cortisol stimulates a catabolic reaction in the body which negates GH’s anabolic function
What are some specific meds that can inhibit GH, especially in children?
Prednisone, dexamethasone, prednisolone
What are three growth syndromes that can be caused by dysfunctional GH?
Dwarfism
Acromegaly
Gigantism
What is dwarfism caused by?
Too little GH before puberty
(impaired secretion or receptors)
What is gigantism caused by?
Too much GH before puberty
What happens in gigantism?
Long bones and flat bones become enlarged due to too much GH before the epiphyseal plates close
What are physical findings of gigantism?
Excessive height
Enlarged hands/feet/skull
What is acromegaly caused by?
Excessive GH after puberty
What are physical findings of acromegaly?
Height does not change (long bones are unaffected)
Flat bones are affected
Enlarged hands/feet/skull
What is the main concern of long-term excessive GH?
Shortened life span
What are other complications of long-term excessive GH?
Cardiomyopathy/cardiomegaly
Neuropathy of hands/feet
Diabetes
Increased risk of malignancy (3x)
Respiratory disease
Arthropathy
