Growth Hormone Flashcards
Describe GH and its major actions
made by AP, works on protein metabolism, carbohydrate metabolism, and lipid metabolism
Discuss species variation and the relevance of this information clinically.
variable among species, ex: GH From Cows is ineffective in humans
Describe whether blood levels of GH are constant or variable.
variable, pulsatile with dependencies on nutrients and sleep in various mammals
Name the hypothalamic hormones that regulate GH.
GHRH (Growth Hormone Releasing Hormone), GHIH (Growth Hormone Inhibitory Hormone aka somatostatin).
Describe major actions of GH on protein metabolism, lipid metabolism, and glucose metabolism.
protein anabolic, increases protein synthesis, muscle mass, and AA uptake; Carbohydrate breakdown to increase blood glucose, hepatic glucose output, and increase insulin resistance. Decreased uptake of glucose by muscles.; Increased lipolysis, decreased fat synthesis and adipose mass
Define IGF-1, its source in the body, and its major actions.
similar in structure and function to insulin. Produced mostly by liver, stimulation of production by GH; Studies have shown it is essential for growth
Describe the structure, source, and actions of somatostatin.
Growth Hormone Inhibitory Hormone, 14 AA long polypeptide, acts on somatotrophs of AP to inhibit GH production
Describe why growth hormone is “diabetogenic”
too much GH is frequently associated with diabetes mellitus because GH production increases blood glucose and insulin resistance; too much GH would cause insulin resistance and BG levels similar to what is seen in diabetes mellitus.
Describe the effect of a lack of GH production during development
panhypopituarism: Dwarfism, slow bone and organ growth, reduced adult size, abnormal body proportions
Describe the role of GH in dwarfism
too little GH or lack of normal GH response
Define what BST is, and why it is used extensively in the dairy industry
bovine somatotropin (Same as GH), It is admin to dairy cows via injection every 14 days to increase milk yield by 40%
Describe the health concerns that come with BST usage.
animals given bST saw an increase in mastitis and other ailments like foot problems which forces use of abx, possibly creating superbugs; bST and IGF-1 both present in milk consumed by humans, bST denatured via pasteurization and GI tract, but IGF-1 survives pasteuration and digestion, and is identical to human IGF-1. Jury still out on effects this has on humans.
Define: Protein metabolism
protein building stimulated by GH
Define: Lipid metabolism
increased lipolysis from secretion of GH
Define: Glucose metabolism
increased lipolysis from secretion of GH
