In this study we document the sensitivity of the leech pharynx to acetylcholine and begin to characterize the acetylcholine receptor mediating this response by examining the effects of selective cholinergic agonists and antagonists on the contractile behavior of the pharynx. The order of potency derived from the EC50 of each agonist was (+/-)epibatidine > acetylcholine (in the presence of physo...

The binding of acetylcholine to pure lipids, and lipids, proteins and lipoproteins extracted from synaptic membranes, was investigated by monolayer and n.m.r. techniques. No specific binding of acetylcholine could be detected at the concentration used, although its muscarinic and nicotinic antagonists [atropine and (+)-tubocurarine respectively] could be shown to interact with the membrane comp...

Background: Asthma is a chronic inflammatory disorder of the airways. The available treatment options have major limitations owing to low efficacy, associated adverse events and compliance issues. Therefore, the health burden of bronchial asthma is increasing globally at an alarming rate, providing a strong impetus for the development of new therapeutics. Myrica sapida is known traditionally in...

Denervation of adult skeletal muscle results in increased sensitivity to acetylcholine in extrajunctional regions of the muscle fiber. This increase in acetylcholine sensitivity is accompanied by a large increase in the level of mRNAs coding for the a-, f3-, Y-, and S-subunits of the acetylcholine receptor. To determine whether muscle activity is sufficient to regulate expression of extrajuncti...

The effect of tail pinch on acetylcholine release in the striatum of freely moving rats was studied by microdialysis immediately after inhalation exposure to toluene (2000 ppm, 2 h) or exposure to air only. It has recently been found that toluene increases extracellular dopamine levels while decreasing acetylcholine release, and that dopamine uptake inhibition increases both extracellular dopam...

- verapamil produces a sustained contraction in isolated biventer-cervicis muscle of chickens between 2-8 days old. from cumulative dose-response curves, ed50 of was calculated for this effect of verapamil. when isolated chicken biventer-cervicis muscle was electrically stimulated, verapamil had no effect on twitch contractures but increased the base line tone of the muscle. glycerol treatment ...

Phospholipases A2 represent the most abundant family of snake venom proteins. They manifest an array of biological activities, which is constantly expanding. We have recently shown that a protein bitanarin, isolated from the venom of the puff adder Bitis arietans and possessing high phospholipolytic activity, interacts with different types of nicotinic acetylcholine receptors and with the acety...

One immunological component of asthma is believed to be the interaction of eosinophils with parasympathetic cholinergic nerves and a consequent inhibition of acetylcholine muscarinic M2 receptor activity, leading to enhanced acetylcholine release and bronchoconstriction. Here we have used an in vitro model of cholinergic nerve function, the human IMR32 cell line, to study this interaction. IMR3...

An endothelium-dependent vasodilator response to acetylcholine has been described recently in patients with coronary artery disease. Those studies determined responses only of large epicardial arteries. Our study was designed to determine the integrated effects of acetylcholine on epicardial diameter, coronary flow, and vascular resistance. Patients (n = 64) with nonstenotic epicardial coronari...