Step I What second messangers do I need to know???
Started by Coastalbarley
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i take boards on tuesday so the help is appreciated
do you have the kaplan biochem book? Its got a pretty good review of second messengers and signaling cascades....it made a pretty big deal of this as well...
Pathways to know....
cAMP
PIP2/IP3/DAG
cGMP
Insulin, growth factors
cAMP vs. PLC-IP3
As a rule of thumb, hypothalamic > cAMP; hypophyseal > IP3
Some important hormones using cAMP
cGMP: Vasodilators
Tyrosine kinase: Growth hormones
Steroid hormones
Based it on adrenal cortex. These receptors are located inside cytoplasm.
Non-steroid hydrophobic hormones
Similar to steroid hormones
As a rule of thumb, hypothalamic > cAMP; hypophyseal > IP3
- CRH/ACTH is cAMP; GHRH is IP3
- FSH/LH/hCG is cAMP; GnRH and oxytocin is IP3
- TSH is cAMP; TRH is IP3
- ADH (V2) is cAMP; ADH (V1) is IP3
- Beta-1 and -2 receptors are cAMP; alpha-1 is IP3; alpha-2 is Gi
Some important hormones using cAMP
- PTH and calcitonin: Their effects are reverse, but they use the same second messenger system
- Glucagon: Maybe the most important one.
cGMP: Vasodilators
- ANP
- EDRF
- NO: Directly stimulates cGMP synthesis
Tyrosine kinase: Growth hormones
- Insulin and IGF-1
- EGF: Herceptin (transtuzumab) binds to these receptors
- FGF/VEGF: Avastin (bevacizumab) binds to VEGF receptors
Steroid hormones
Based it on adrenal cortex. These receptors are located inside cytoplasm.
- Zona glomerulosa: Aldosterone
- Zona fasciculata: Glucocorticoids
- Zona reticularis: Sex hormones (estrogen, progesterone, testosterone)
- Vitamin D
Non-steroid hydrophobic hormones
Similar to steroid hormones
- Thyroid hormones: So for thyroid gland: TRH is IP3, TSH is cAMP and thyroid hormones have intranuclear receptors.
- Vitamin A
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ya i would definitely know the second messengers. I had 1-2 questions on it and one of my friends had even more than that. So know them well and then those will be easy points.
where at in the book, i have it but never read it
haha seriously dude? Open it up and look at the table of contents or search in the index. C'mon, i cant study for you too.
ahh fair enough, thanks for the heads up though
This is a streamlined review sheet of receptors/2nd messengers I downloaded from here a while back. It looks pretty comprehensive.
According to FA, GHRH is cAMP
Yeah, I'm going with first aid 2014 after finding that out. I got NBME question wrong about signalling pathways cuz I couldn't remember which one belongs to which group so I was searching for better way to remember and found this post, but not so helpful. So, I will be coming up wtih my own way to remember it.
Do you have a better way to remember them?
actually, I thought this was a good mnemonic, and i think that was the only error.
i just go with FLAT ChAMP and goat hag per first aid
Costanzo LS, Physiology, 5th Ed., Chapter 9, p. 390: "Phospholipase C Mechanism (IP3, Ca2+) ... GHRH". Op. cit., p. 399: "...In initiating its action on the somatotroph, GHRH binds to a membrane receptor, which is coupled through a G s protein to both adenylyl cyclase and phospholipase C. Thus, GHRH stimulates growth hormone secretion by utilizing both cAMP and IP 3 /Ca 2+ as second messengers."
The same table is also in BRS Physiology, Chapter 7, p. 224.
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myxedema you have outdone yourself. So, would you argue that they wouldn't directly ask which mechanism GHRH uses since it's both?
