“At a tannin concentration of 10 micrograms/ml, tannin inhibited the rise in intracellular cAMP in cells stimulated with either epinephrine or bradykinin but had no effect on bradykinin-stimulated prostaglandin E2 release.”
“Pretreatment with 100 micrograms/ml tannin completely inhibited the rise in intracellular free calcium in response to epinephrine but had no effect on the calcium response to bradykinin.”
“ Tannin pretreatment blunted the subsequent response to epinephrine beginning at a tannin concentration of 10 micrograms/ml.”