C fullerenes selectively inhibit BK but not K channels in pulmonary artery smooth muscle cells.

Possessing unique physical and chemical properties, C fullerenes are arising as a potential nanotechnological tool that can strongly affect various biological processes. Recent molecular modeling studies have shown that C fullerenes can interact with ion channels, but there is lack of data about possible effects of C molecule on ion channels expressed in smooth muscle cells (SMC). Here we show both computationally and experimentally that water-soluble pristine C fullerene strongly inhibits the large conductance Ca-dependent K (BK), but not voltage-gated K (K) channels in pulmonary artery SMC.

C fullerenes disrupt cellular signalling leading to TRPC4 and TRPC6 channels opening by the activation of muscarinic receptors and G-proteins in small intestinal smooth muscles.

The effect of water-soluble pristine C fullerene nanoparticles (CNPs) on receptor-operated cation channels formed by TRPC4/C6 proteins in ileal smooth muscle cells was investigated for the first time. Activation of these channels subsequent to acetylcholine binding to the expressed in these cells M and M muscarinic receptors represents the key event in the parasympathetic control of gastrointestinal smooth muscle motility and cholinergic excitation-contraction coupling. Experiments were performed on single collagenase-dispersed mouse ileal myocytes using patch-clamp techniques with symmetrical 125mM Cs solutions and [Ca] 'clamped' at 100nM in order to isolate the muscarinic cation current (mI).

Inhalation anaesthetic isoflurane inhibits the muscarinic cation current and carbachol-induced gastrointestinal smooth muscle contractions.

Gastrointestinal tract motility may be demoted significantly after surgery operations at least in part due to anaesthetic agents, but there is no comprehensive explanation of the molecular mechanism(s) of such adverse effects. Anesthetics are known to interact with various receptors and ion channels including several subtypes of transient receptor potential (TRP) channels. Two members of the canonical subfamily of TRP channels (TRPC), TRPC4 and TRPC6 are Ca-permeable cation channels involved in visceral smooth muscle contractility induced by acetylcholine, the primary excitatory neurotransmitter in the gut.

Functional and pharmacological characterization of volume-regulated anion channels in human normal and cystic fibrosis bronchial and nasal epithelial cells.

Volume-regulated anion channels (VRACs) are widely present in various cell types and have important functions ranging from regulatory volume decrease to control of cell proliferation and apoptosis. Here we aimed to compare the biophysical features and pharmacological profiles of VRAC currents in healthy and cystic fibrosis (CF) respiratory epithelial cells in order to characterize these currents both functionally and pharmacologically. Whole-cell electrophysiology was used to characterize the VRAC current in normal (16HBE14o-; HBE) and CF cell lines (CFBE14o-; CFBE), as well as in native human nasal epithelial cells.