Second messengers for.... - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 02-12-2011
usmledee's Avatar
USMLE Forums Veteran
 
Steps History: 1+CK+CS
Posts: 257
Threads: 69
Thanked 122 Times in 63 Posts
Reputation: 132
Molecular Second messengers for....

2nd messenger for :
* Motilin ???
* GIP ???
* Ghrelin ???

Anyone know ???
Reply With Quote Quick reply to this message



  #2  
Old 02-12-2011
usmledee's Avatar
USMLE Forums Veteran
 
Steps History: 1+CK+CS
Posts: 257
Threads: 69
Thanked 122 Times in 63 Posts
Reputation: 132
Default Nobody??

No ones knows these???
Reply With Quote Quick reply to this message
  #3  
Old 02-12-2011
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 590
Threads: 31
Thanked 1,232 Times in 411 Posts
Reputation: 1256
Default

They're all GPCR's, so that narrows it down. And motilin and ghrelin are probably similar? If I had to guess on a test I'd choose IP3-DAG, just because they are peptides and it seems like a safe bet...

Anyone know the answer?
Reply With Quote Quick reply to this message
 
  #4  
Old 02-12-2011
USMLE Forums Addict
 
Steps History: 1 + CK
Posts: 116
Threads: 7
Thanked 343 Times in 94 Posts
Reputation: 353
Default

Follow the general concept. If contraction of smooth muscle or exocytosis (both need Ca++) is involved, then it is DAG/IP3 system; otherwise it is cAMP system.

Motilin leads to contraction of smooth muscle in GIT: DAG/IP3.

Ghrelin is a gut-derived peptide and an endogenous ligand for the growth hormone (GH) secretagogue receptor. Exogenous ghrelin stimulates the release of GH (potently) and adrenocorticotropic hormone (ACTH) (moderately). DAG/IP3.

There r 2 hormone families in GIT. Gastrin and Secretin. GIP is from secretin family and 2nd messenger for this family is cAMP. 2nd messenger for gastrin family is Ca++.

I remember one q from either uw or kaplan in which they give the name of one hormone and ask which other hormone is most similar. they were asking about the hormone families.

Q. What are the two hormone families? Name the hormones in each?
A. Gastrin (and CCK) and Secretin (VIP, GIP, Glugagon)
Q. What is the second messenger for homones in the Gastrin family?
A. Calcium
Q. What is the second messenger for hormones in the secretin family?
A. cAMP
Q. What makes a hormone family?
A. Same receptor and second messanger

Finally, i am not that much sure about Ghrelin. it is just my educated guess.
Reply With Quote Quick reply to this message
The above post was thanked by:
Mondoshawan (02-12-2011), ms.med (02-12-2011), surez18 (05-02-2011), usmle0987 (02-12-2011), usmledee (02-12-2011)
  #5  
Old 02-12-2011
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 590
Threads: 31
Thanked 1,232 Times in 411 Posts
Reputation: 1256
Thumbs Up

Very clear - and a widely applicable concept!
Reply With Quote Quick reply to this message
  #6  
Old 02-12-2011
USMLE Forums Addict
 
Steps History: 1 + CK
Posts: 116
Threads: 7
Thanked 343 Times in 94 Posts
Reputation: 353
Default

one more general concept. if a hormone stimulates one substance and inhibits other, it is more likely to be cAMP associated. This is because, phosphorylation by cAMP-kinases activates some proteins and inhibits others.
GIP inhibits gastic acid release and stimulates insulin release.
Reply With Quote Quick reply to this message
The above post was thanked by:
Mondoshawan (02-12-2011), surez18 (05-02-2011)
  #7  
Old 02-12-2011
usmledee's Avatar
USMLE Forums Veteran
 
Steps History: 1+CK+CS
Posts: 257
Threads: 69
Thanked 122 Times in 63 Posts
Reputation: 132
Default

Awesome concepts here. Thank u.
Reply With Quote Quick reply to this message



Reply

Tags
Molecular-Biology-

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)