[Question] how do you actually verify mechanism
Slightly embarrassed to be asking this, but: how do you actually verify mechanism.
Asked a question here that I thought was stupid and got three papers back. Best thread I have been in on this site.
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.
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.
Not medical advice, obviously, and nothing here is approved for human use. One person with a spreadsheet.
best — the order this archive was captured in
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.
Spent an evening on the receptor distribution literature and the side-effect map suddenly stopped looking random.
albumin binding is most of the half-life story