Q. M1 or M3 receptor present in stomach/parietal cells?

[Aumsai]

Q. FA 2014 (Autonomic drugs) p.244 & GI p.347 says M3 receptor is present on stomach/parietal cells but kaplan, wikipedia and some other sources mention M1 receptor is present in stomach to increase gastric acid secretion.Which one to follow? Can anybody pls shed light on this confusing part..thanks.

[CleverFOX]

Speaking sensibly it doesn't matter because the drugs which blocks muscarinic receptors block M1-M5 all of them...and the drugs which are parasympathomimetic(stimulates M receptors) stimulates all of them M1 to M5....but I would go with Kaplan notes on this...which says:

M1 for Stomach glands ---> secretions
M3 for muscles in the stomach ---> peristalsis

[quacky.mcquacky]

Originally Posted by Aumsai

Q. FA 2014 (Autonomic drugs) p.244 & GI p.347 says M3 receptor is present on stomach/parietal cells but kaplan, wikipedia and some other sources mention M1 receptor is present in stomach to increase gastric acid secretion.Which one to follow? Can anybody pls shed light on this confusing part..thanks.

Both receptors are there.
But, there are M3 receptors on parietal cells. There are (according to wikipedia) M1 receptors on ECL cells. M1 receptors are found in enteric and central nervous system. M3 receptors are those found on exocrine glands....(I found an article on pubmed stating they found M3 subtype on parietal cell. Wikipedia says the same thing...)
As CleverFOX said though, it doesn't really matter.

[Aumsai]

Thanks cleverfox and quacky.mcquacky for explaining the concept to analyse in broader way.