Search This Blog

Monday, May 21, 2012

Agonists, inverse, partial and full


Let's see whether you understand inverse antagonists etc:
  1. I you combine an agonist with a competitive antagonist you will
    A) never obtain a maximal response
    B) get a negative response like with an inverse agonist alone.
    C) eventually will obtain a maximal effect when increasing the agonist concentration.
    D) get no or only a very small effect.
  1. If you combine an antagonist with an inverse agonist you will
    A) get a positive response instead of a negative one as you would in the absence of the inverse agonist.
    B) get no response when increasing the antagonist concentration.
    C) will get an increased negative effect.
    D) will form a black hole.
  1. If you combine a partial agonist with an inverse agonist you will get
    A) a maximal effect.
    B) a negative effect if you keep increasing the inverse agonist concentration.
    C) a negative effect if you keep increasing the partial agonist concentration.
    D) will precipitate a Big Bang.
Goods luck: I want to see responses by each of you in the comment section!

6 comments:

  1. Here's my attempt. Perhaps this is a good way for me to get over my fear of doing practice questions...
    1. C (b/c agonist + competetive antagonist aka competetive inhibitor fight for spots. If one increases [agonist] it will beat out the comp antagonist for spots)
    2. B (b/c antagonist inhibits effects of the inverse agonist so if [antagonist] is increased, the inverse agonist will be inhibited more and more)
    3. B (b/c partial agonist increases effect in the positive, inverse agonist increases effect in the negative, so increasing [inverse agonist] would increase the negative effect.

    ReplyDelete
  2. #1 - I think that even with an increase in the agonist, the antagonist will still reduce the effects of the agonist, so you will (A) never obtain a maximal response.
    #2 - I agree with Natalie, so (B).
    #3 - B, almost 100% sure.

    ReplyDelete
  3. Courtney, I was teetering between A and C for #1. haha. At least I know one of us is correct since the other answers were definitely not correct :)

    ReplyDelete
  4. 1) A . . . because wouldn't the Antagonist competitively inhibit the receptor site therefore not allowing maximal binding of Agonist
    2) B I agree with the others
    3) B

    ReplyDelete
  5. Answers are
    C
    B
    B
    Congrats.
    Case 1: It is all a matter of mass action dynamics: when you keep on increasing the agonist concentration, at a constant antagonist level, you will eventually displace all of the antagonist from the receptors, and then you have a maximal effect, as per the efficacy of the antagonist.

    ReplyDelete
  6. still trying to get the hang of these pharmacology questions...hopefully I get used to them eventually!

    ReplyDelete