Possible Interaction: Acetylcholine and Procaine

“Some important differences are a lower affinity for acetylcholine and its binding of procaine.”

“5 Small concentrations of procaine markedly inhibited responses to acetylcholine and produced a partial block of the neuronally evoked contractions.”

“ Procaine in close-range, short-time application is as potent an inhibitor of acetylcholine action as DTC.”

“ Acetylcholine (or benzoylcholine) and procaine (or other local anesthetic esters) can act as competitive inhibitors for the same enzyme.”

“In the cells stimulated with bradykinin and acetylcholine , 10 μM each of procaine and lidocaine significantly inhibited NO production by 35% and 20%, respectively.”

“ Acetylcholine effects were not antagonized by eitherm-cholinolytic (atropine) orn-cholinolytic (pentolinium) agents, but were markedly inhibited by procaine.”

“From these observations, it is concluded that at low concentrations procaine acts … muscarinic receptors in the guinea-pig taenia caecum while high concentrations of procaine may … to acetylcholine , substance P and KCl by inhibiting the Ca-induced Ca release … site or by reducing the transmembrane Ca influx during depolarization.”

“In normal Tyrode solution (37°C), procaine (10–100 μmol/l) caused a parallel shift to the right of only the dose-response curve of acetylcholine (pA2 value, 5.11).”

“ Procaine (5–500 μol/l) caused a concentration-dependent inhibition of contractions induced by PGI2 (20 nmol/l and 1 μmol/l) and by equieffective concentrations of ACh (20 nmol/l and 0.4 μol/l, respectively).”

“Relative to etidocaine, procaine displayed about 10-fold lower potency in antagonizing acetylcholine and its inhibitory effect, unlike that of etidocaine, was rapidly reversed by washout.”

“When physostigmine (10‐5 to 10‐3 M) or procaine (3 × 10‐5 to 10‐3 M) was added to the acetylcholine pulses , a fast decay component of the current appeared which shortened to a time constant of 0.5 ms for the maximal drug concentrations.”