title: Different sensitivity of miniature endplate currents in rat external and internal intercostal muscles to the acetylcholinesterase inhibitor C-547 as compared with diaphragm and extensor digitorum longus.
abstract: Derivative of 6-methyluracil, selective cholinesterase inhibitor C-547 potentiates miniature endplate currents (MEPCs) in rat external intercostal muscles (external ICM) more effectively than in internal intercostal muscles (internal ICM). Effect of the C-547 on intercostal muscles was compared with those on extensor digitorum longus (EDL) and diaphragm muscles. Half-effective concentrations for tau of MEPC decay arranged in increasing order were as follows: EDL, locomotor muscle, most sensitive = 1.3 nM, external ICM, inspiration muscle = 6.8 nM, diaphragm, main inspiration muscle = 28 nM, internal ICM, expiration muscle = 71 nM. External ICM might therefore be inhibited, similarly as the limb muscles, by nanomolar concentrations of the drug and do not participate in inspiration in the presence of the C-547. Moreover, internal ICM inhibition can hinder the expiration during exercise-induced fast breathing of C-547- treated experimental animals.
authors.affiliation: A.E.Arbuzov Institute of Organic and Physical Chemistry, Russian Academy of Sciences, Kazan, Russia.
authors.forename: K
authors.initials: K
authors.lastname: Petrov
authors.forename: I
authors.initials: I
authors.lastname: Kovyazina
authors.forename: V
authors.initials: V
authors.lastname: Zobov
authors.forename: E
authors.initials: E
authors.lastname: Bukharaeva
authors.forename: E E
authors.initials: EE
authors.lastname: Nikolsky
authors.forename: F
authors.initials: F
authors.lastname: Vyskocil