Rubinstein_1986_Eur.J.Pharmacol_123_145

Reference

Title : A study of the contractile response to acetylcholine in human ileal and detrusor muscle: origin of the low efficacy of acetylcholine - Rubinstein_1986_Eur.J.Pharmacol_123_145
Author(s) : Rubinstein R , Nissenkorn I , Cohen S
Ref : European Journal of Pharmacology , 123 :145 , 1986
Abstract :

In Krebs solution (3.36 mM Ca2+), the maximal contractile response of human ileal and urinary bladder detrusor muscle to acetylcholine (ACh) was 40-60% that to carbachol (CCh). The maximum response to ACh was reached at a bath concentration of about 1 microM and was maintained throughout a range extending to 100 microM. In the presence of neostigmine (0.1 microM), the maximum response to ACh reached the level of that of CCh. However, bioassay of bath concentrations of ACh at various points of the maximal response in the absence of neostigmine revealed only slight to insignificant diminution of the applied concentration of ACh. Joint application of ACh and CCh generated a dose-response profile consistent with a model of competitive antagonism between a full agonist (CCh) and a partial one (ACh). Also, choline (100 microM) reduced the maximum response to ACh in the presence of neostigmine and that to CCh to 60-80% of control. These observations are consistent with a mechanism whereby intact cholinesterase together with its substrate ACh and possibly a breakdown product of ACh constitute a filter or diffusional barrier regulating the flow of agonist from the enzyme compartment to the receptor compartment.

PubMedSearch : Rubinstein_1986_Eur.J.Pharmacol_123_145
PubMedID: 3709660

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Citations formats

Rubinstein R, Nissenkorn I, Cohen S (1986)
A study of the contractile response to acetylcholine in human ileal and detrusor muscle: origin of the low efficacy of acetylcholine
European Journal of Pharmacology 123 :145

Rubinstein R, Nissenkorn I, Cohen S (1986)
European Journal of Pharmacology 123 :145