does receptor actually matter or is it forum lore at this point
Slightly embarrassed to be asking this, but: does receptor actually matter or is it forum lore at this point.
Spent an evening on the receptor distribution literature and the side-effect map suddenly stopped looking random.
Tried to build a mental model from mechanism alone and produced a confident prediction that the trial data flatly contradicted.
The half-life explanation was the thing that made weekly dosing intuitive for me rather than arbitrary.
Would rather be corrected in public than confident in private.
best — the order this archive was captured in
The incretin effect is the observation that oral glucose provokes a larger insulin response than intravenous glucose at matched glycaemia, and the difference is mediated by gut hormones. That is the foundation the whole class sits on.
Why mechanism talk keeps misleading people, including me.
A mechanism tells you a direction. It does not tell you a magnitude, a timescale, or whether the pathway is operative at the exposures involved. "Receptor X is expressed in tissue Y" is a fact; "therefore effect Z in a person" is a hypothesis with several missing steps.
The corrective is boring and it works: ask whether the evidence is preclinical or human, ask what exposure was used, and read the limitations section before the abstract. Most of the confidently wrong posts on this board — several of them mine — skipped all three.
gastric emptying slows, it does not stop
GIP is the arm people argue about because the biology is genuinely unsettled
Is that from a human study or a preclinical model?
Is there any human data on that mechanism yet?
Does the effect persist with continued dosing or does tolerance develop?
GIP receptor biology is genuinely unsettled — there is a live argument about agonism versus antagonism at the receptor — and the clinical results are robust regardless, which is an uncomfortable and interesting position.
preclinical is not clinical and rodents are not small people
a mechanism you can state is not a mechanism you have demonstrated
incretin effect first, then everything else in this board makes sense
incretin effect first, then everything else in this board makes sense
Adding the caveat the paper itself makes in its limitations section, which is stronger than anything in this thread.
Asked a question here that I thought was stupid and got three papers back. Best thread I have been in on this site.
Was completely wrong about the gastric emptying story in a thread here two years ago. Someone corrected me with a citation and I have not made that mistake since.
Which receptor arm are you attributing that to?
What was the exposure in that experiment relative to therapeutic?
Do you have the paper, or a summary of it?
The GIP question, which is the most interesting unsettled thing in this field.
Dual agonism at GIP and GLP-1 receptors produces clinical results that are robust and well replicated. What is not settled is the mechanism by which the GIP arm contributes — there is a genuine scientific argument about agonism versus antagonism at that receptor, with reasonable people and real data on both sides.
It is worth sitting with that. The clinical effect is not in doubt; the explanation is. That is an ordinary state of affairs in pharmacology and it is a good corrective to the confident mechanistic stories that circulate here.
dose response is not linear and nobody should assume it is
Went looking for human data on a mechanism everybody here asserts. Found preclinical work and one small study. That was clarifying.
Read the primary paper after arguing about the summary for a fortnight. The discussion section said almost the opposite of what the thread had concluded.
mechanism explains a direction, not a magnitude
read the discussion section, that is where the honesty lives
- 1Does the effect persist with continued dosing or does tolerance develop?7 comments in this branch · started by u/whois_wanda
- 2Do you have the paper, or a summary of it?7 comments in this branch · started by u/bastian_ekstrom