Test 3: lecture 6 Flashcards
endocrine vs paracrine vs autocrine
endocrine→ secreted, enters blood stream and can act everywhere a receptor is located
paracrine- local hormone control
autocrine- hormone released by cell acts on that same cell
four general classes of hormones
proteins and peptides
steroids
derivatives of tyrosine (amines)
fatty acid derivatives (e.g. prostaglandins)
____hormones are stored in secretory vesicles until needed
Protein and peptide
___hormones are synthesized from cholesterol and are not stored.
Steroid
___hormones are derived from tyrosine and are stored
Amine
peptide hormone synthesis
N-terminal signal peptide tells the golgi apparatus to package these hormones into secretory vesicles for secretion
characteristics of hormone secretion:
Incredibly ____concentration of hormones
_____ feedback control
___ variations in hormone release
low
Negative
Cyclical
____ are dissolved in the plasma (short half-life).
Peptides and catecholamines
(water soluble)
____ hormones are bound to plasma proteins given them a ___ half-life.
Steroid and thyroid
long (don’t get dissolved as quickly)
how are hormones removed from blood
- Binding with tissues
- Metabolic destruction by tissues
- Excretion by liver into the bile
- Excretion by kidneys into the urine
based on how fast they are secreted
protein-bound hormones are cleared slower than free hormones.
three locations for hormone receptors
cell membrane
cytoplasm
nucleus
where are the receptors for peptide and catecholamines
hormone receptor on the cell membrane
water soluble
where are the steroid hormone receptors
in the cytoplasm
where are the thyroid hormone receptors
in the nucleus
one way for a cell to regulate hormones is to ___ the receptors
decrease or increase the number of receptors for a specific hormone
peptide and catecholamines depend on ____ for intracellular signaling
second messengers
Adenylyl cyclase - cAMP
Phospholipids: IP3 and DAG
Calcium-calmodulin
cAMP second messenger
peptide hormone can’t get into cell, binds to receptor on the surface
this causes ATP → cAMP with the help of enzyme adenylyl cyclase
cAMP then is used to activate cAMP dependent protein kinase
which is used to activate protein and produce cell response
cAMP is formed by an amplification step therefore a very small amount of hormone can create very large effect
phospholipid second messenger
peptide/catecholamine hormones can’t get into cell, need to use surface receptors
binding of hormone causes G protein to increase the amount of phospholipase C which is used to form DAG and IP3 from a phospholipid
IP3 causes release of calcium from ER and mitochondria → protein activation. calcium also binds to calmodulin → protein phosphorylation
DAG activated PKC → protein phosphorylation
calcium calmodulin
peptide/catecholamine hormones can’t get into cell, need to use surface receptors
calcium- calmodulin works on Calcium channels to bring calcium into the cell
can also work with : IP3 from the phospholipid second messenger
binding of peptide hormone causes G protein to increase the amount of phospholipase C which is used to form DAG and IP3 from a phospholipid
IP3 causes release of calcium from ER and mitochondria → protein activation. calcium also binds to calmodulin → protein phosphorylation
DAG activated PKC → protein phosphorylation
how to measure blood hormone concentration
Hormone-specific antibody
Radio-labeled standard Hormone
Your test sample
Antibody is limited.
Equilibrium
Isolate Ab-hormone complex
hormones produced by anterior pituitary
all hormones produced by the ___ are protein and peptide hormones
pituitart
hypothalamus produces what type of hormones
TRH, CRH, GHRH, GHIH, GnRH → peptide hormones
PIH → amine hormone
where are hormones from the hypothalamus released to get to the anterior pituitary
median eminence
then taken by the hypothalamic-hypophysial portal vessel
HPA
___ produces ADH
supraoptic nucleus in the hypothalamus
will carry ADH down the hypothalamic-pituitary tract to the posterior pituitary to be stored until needed
___ produces oxytocin
paraventricular nucleus in the hypothalamus
will carry oxytocin down the hypothalamic-pituitary tract to the posterior pituitary to be stored until needed
growth hormone
protein hormone made by the anterior pituitary gland
also called Somatotropic hormone or somatotropin
Growth hormone affects all tissues
191 amino acids, 22 kD (protein hormone)
Considerable species specificity (can’t use human GH in other animals)
metabolic effect of growth hormone on protein deposition
Promote protein deposition
- Enhance amino acids uptake
- Enhance transcription and translation
- Decrease protein breakdown
metabolic effect of growth hormone on fat
enhance fat utilization for energy
metabolic effect of growth hormone on carbs
Decrease carbohydrate utilization - diabetogenic
- Decrease glucose uptake –insulin-resistance
- Increase glucose production by liver
- Increase insulin secretion
overall effect of GH
more protein, less fat, decrease utilization of carbs → diabetes (increase blood glucose)
will an older or younger person have more GH
a younger
amount of GH decreases with age
GH causes the liver to produce ___
somatomedins
mediates GH effect
somatomedin C (IGF-I): similar to proinsulin
in pygmies: high GH, low IGF-I (somatomedin C)
somatomedin C
Growth hormone causes liver to produce several potent somatomedins.
Somatomedin C (IGF-I → insulin-like growth factor ): similar to proinsulin.
Plasma concentrations of GH and IGF-I are highly correlated with body size
pygmies have normal GH but low amounts of IGF-I
___ is made by the hypothalamus to stop GH release
Growth hormone-inhibitory hormone (GHIH) (type of peptide hormone)
also called a Somatostatin
____ is made by the hypothalamus to stimulate GH release
Growth hormone-releasing hormone (GHRH) (type of peptide hormone)
what are some activities that release GH
sleep and strenuous exercise
what will starvation do to the release of GH
it will stimulate the release of GH
what are some factors that will stimulate GH release
Decreased blood glucose
Decreased blood FFA
Starvation
Trauma
Stress
Exercise
Deep sleep
GHRH
what are some factors that will inhibit GH release
Increased blood glucose
Increased blood FFA
Aging
Obesity
Growth hormone
GHIH (somatostatin)
dwarfism is caused by ___
disorder in GH
not enough GH during childhood
gigantism is caused by ___
excessive levels of GH during childhood
will eventually develop diabetes, because GH causes increased blood glucose
acromegaly
caused by too much GH during adult hood
big organs, tissues
different from gigantism because long bones don’t get bigger only connective tissue stuff gets bigger
