Is it M3 RECEPTOR or M1 RECEPTOR a/w hcl secretion?

Is it M3 RECEPTOR or M1 RECEPTOR a/w hcl secretion ?

M3 receptor is associated with increased secretions.

As taught in pharma

M1 receptor agonist oxotremorine causes gastritis (by inc hcl secretion) …pirenzepine telenzepine are hence selective m1 antag(anticholinergics ) rx of gastritis …

M3 R agonist in git act as prokinetics and diarrehea…

Sir, how does Pirenzepine inhibit HCl secretion then?