“Combined treatment with Ninjinto and pirenzepine significantly increased the release of plasma somatostatin (AUC0→240 min) compared with administration of Ninjinto alone or placebo.”
“Ninjinto appeared to induce the release of substance P and motilin into plasma mainly through the activation of M1 muscarinic receptors, and pirenzepine may affect the pharmacologic action of Ninjinto by the elevation of plasma substance P, motilin, and somatostatin.”