Possible Interaction: Carbachol and Procaine

“ Procaine (30 mM) blocked the carbachol (50 microM) contractions in bladders but not in taenia.”

“In the presence of procaine, carbachol was inhibited and only slightly reduced the Ca2+-deposits on the plasma membranes.”

“2 Procaine inhibited the catecholamine secretion evoked by 500 μm carbachol (CCh) with an IC50 of 35 μm and the associated calcium influx (IC50 60 μm).”

“5 In agreement with the ion flux studies, procaine inhibited the inward current evoked by CCh.”

“The 22Na uptake due to carbachol was inhibited by atropine, procaine or CoCl2; the response to Substance P was inhibited by CoCl2 only.”

“The local anaesthetics tetracaine and procaine inhibited both the transient and sustained phases of the responses to carbachol and phenylephrine; responses to Substance P and to the divalent cationophore, A23187, were largely refractory to this effect.”

“ Procaine inhibited the increase in O 2 consumption due to carbachol , but not that due to substance P. When both carbachol and substance P were presented to the tissues in series and in the absence of external Ca, the second agonist failed to produce a response.”

“ Procaine (1.0 mM), however, blocked the response to carbachol but not substance P. These results support an hypothesis suggesting that Co++ blocks inward transport of Ca++ while procaine interferes with the transduction mechanism linking the muscarinic receptor to the Ca++ channel.”

“ Procaine (27×10-5 g/ml; 1 mM) supPressed both the depolarization and the desensitization induced by Carb.”