Blockade by 2,2′,2″‐tripyridine of the nicotinic acetylcholine receptor channels in embryonic Xenopus muscle cells

Abstract

1 The effects of 2,2',2"-tripyridine on the nicotinic acetylcholine (ACh) receptor channels were studied in the cultured myocytes of 1-day-old Xenopus embryos. 2 2,2',2"-Tripyridine depressed the amplitude of iontophoretic ACh-induced current at a low frequency of 0.7 Hz stimulation and it not only decreased the initial responses but also enhanced the run-down of ACh-induced current at higher frequency stimulation of 7 Hz and 30 Hz. 3 Single ACh channel recordings showed that 2,2',2"-tripyridine decreased the channel conductance, the opening frequency and mean open time of both types of low-and high-conductance channels. 4 These results suggest that the blocking actions of 2,2',2"-tripyridine on ACh receptor channels in the skeletal muscle may contribute to the depression of the nerve-evoked contraction of the mouse diaphragm as reported previously.

Synthesis, characterization, and evaluation of biological activities of new 4′‐substituted ruthenium (II) terpyridine complexes: Prospective anti‐inflammatory properties

“…[67] The blocking actions of 2,2 0 ,2 00 -terpyridine on acetylcholine receptor channels in the skeletal muscle may contribute to the depression of the nerve-evoked contraction. [68] The kinetic studies show that the reaction of tpy with submaxillary nerve growth factor protein 7 s NGF occurs via a two-step process involving first a rapid, apparent second-order step (k 1 = 1 × l0 6 M −1 s −1 ) to form a 7 s NGF-Zn 2+ chelator monocomplex, then a slow step to form a bis (tpy)-Zn (I1) complex and activated 7 s NGF in an apparent first-order process (k obsd = 0.10 min −1 ). [69] The synthesized complexes bearing ligands 4 or 5 show different cytotoxic activity.…”