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Lv 4
? asked in Science & MathematicsMedicine · 1 decade ago

How does one know which drugs are mediated by a GPCR?

Does the difference simply lie in knowing whether a particular drug is centrally- versus peripherally-acting?

Update:

Thanx, Spreezie ;-) ;-). I skimmed that link. I should read it more closely again. Thanx, man.

I know a number of drugs are mediated by a GPCR, but not sure how to recognize which ones.

I've already mentioned that I asked this Q to mdGreg C. I hope he answers, too. We talked about this before, but not sure if, this, specifically. Either that, or I can't recall what he said.

AzR gives killer answers regarding these things, too. Maybe he will answer.

Update 2:

Thanx, mdGreg C :-). With your mention of agonist, I immediately remember what we talked about WRT GPCR.

What is TLR? Tonic labyrinthine reflex? If yes, I want to look something up. I'll come back, later...

Update 3:

You probably meant, toll-like receptors?

Update 4:

So, the diff between GPCR's and TLR's is that the latter is involved in physiological processes and the former with immunological processes. Correct?

Now, with GPCR's, if it is turned on by an agonist, a threshold will be reached, such as is the case in tolerance. Similarly, with TLR, it may be turned on by a ligand of microbial nature, such as a pathogen. And, even though there are several reactions possible, the end result will be some threshold (if left unchecked), related to inflammation, yes?

Am I way off in left-field, here? Did I totally miss what you were getting at?

Update 5:

Sorry, above: GPCR's: physiological processes and TLR's: immunological processes. I had that backwards.

Update 6:

mdGreg C, I am rethinking the likeness of the processes involved with a GPCR WRT TLR's. I'm not sure if a similar thing happens with TLR's. I really don't know. I have just read that a variety of bacterial components induce TLR2 mRNA *upregulation* while *downregulating* TLR4 mRNA. Just an example. But, apparently, TLRs have many structural and cell signaling features in common, but, perhaps the consequences of TLR stimulation depends on the TLR itself (there are 13 of these things), the nature of the ligand, and the cell type expressing the TLR?

Update 7:

I suppose, regardless of what I said directly above, there would still be a threshold...

Update 8:

I have read that abnormal TLR4 expression and signaling may contribute to the pathogenesis of insulin resistance in humans.

In Type II diabetic and obese people, TLR4 increases with NFkappaB signaling and this is accompanied by elevated expression of the NFkappaB-regulated genes interleukin (IL)-6 and superoxide dismutase (SOD)2.

http://www.ncbi.nlm.nih.gov/pubmed/18633101?ordina...

If I am reading this right, well, there's something weird about this. Don't HIV-1 protease inhibitors block TLR4-induced NF-kappa B activation (also, TLR-2)? But, if I have logically deduced all of this (which I may not have), it seems there is an implication that PI could be helpful in Type II diabetes.

3 Answers

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  • Anonymous
    1 decade ago
    Favorite Answer

    I Suppose the Question Really is, Whether the Primary Receptor is GPCR and the Ligand Acts as an Agonist.

    Of Interest:

    http://en.wikipedia.org/wiki/Arrestin

    [I Suppose the Bottom Line is that if a GPCR is "Turned On", for Whatever Reason, then it is Subject to Active Down-Regulation, On the Cellular Level. This Implies Some "Threshold" was Established. Would One Expect Something Similar In TLRs?]

    EDIT: Hey K, Yeah Toll-Like Receptors.

    EDIT: K, I am Not Aware of a Prominent Difference In the Tissue Distribution of These Receptors, Maybe AzR Knows. My Interest Lies In the Down-Regulation of the Insulin Receptor and Type II Diabetes, Again, Something to "Play" With.

    Of Interest:

    http://en.wikipedia.org/wiki/Insulin_receptor

    http://www.ncbi.nlm.nih.gov/pubmed/18060381

  • Spreedog
    Lv 7
    1 decade ago

    Wikipedia has a surprisingly good overview of G protein-coupled receptors.

    http://en.wikipedia.org/wiki/G_protein-coupled_rec...

    According to Wiki - "G protein-coupled receptors are . . . the target of around half of all modern medicinal drugs."

    But the reference cited is not a highly reputable medical journal.

    I'll bet mdGreg will know this one with more scientific evidence than Wiki.

    Source(s): MD
  • vivian
    5 years ago

    If you’ve been diagnosed with diabetes, it’s very important that you learn all you can about your disease and the treatment options available to you. Learn here https://tr.im/YYO5F

    One way to approach diabetes is to use integrative holistic medicine, also known as alternative medicine, a medical specialty that focuses on caring for the whole person, treating and preventing disease, and empowering patients to create conditions for optimal health.

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