In single cells, isolated by enzymatic digestion from the circular muscle layer of the lower esophageal sphincter (LES), acute experimental esophagitis (AE) alters signal transduction in response to a maximally effective dose of acetylcholine. In normal LES contraction was inhibited by M3 >> M1 or M2 antagonists. In AE inhibition by M2 antagonists increased significantly so that contraction was...

Naik, Jay S., Zoran Valic, John B. Buckwalter, and Philip S. Clifford. Rapid vasodilation in response to a brief tetanic muscle contraction. J. Appl. Physiol. 87(5): 1741–1746, 1999.—To test the hypothesis that vasodilation occurs because of the release of a vasoactive substance after a brief muscle contraction and to determine whether acetylcholine spillover from the motor nerve is involved in...

MORITA, T., SuzuKI, T., KoNDO, S. and TSUCHIDA, S. Effects of Noradrena line and Acetylcholine on Ureteral Peristalsis. Tohoku J. exp. Med., 1983, 141 (4), 489-490 Experiments in vitro were performed to compare effects of noradrenaline and acetylcholine on the pyeloureter, both of which activate ureteral peristalsis. Noradrenaline elevated the baseline renal pressure to accelerate the ureteral ...

Effects of exogenous acetylcholine on single-unit aortic baroreceptors were studied using a rabbit in vitro aortic arch/aortic nerve preparation. The arch was perfused with Krebs-Henseleit solution at constant pressure while simultaneously recording arch diameter and baroreceptor discharge frequency. Administration of acetylcholine over a wide range of concentrations (10` to 10` mol/L) evoked m...

objective: the use of drugs with herbal origin is increasing for treatment of gastrointestinal (gi) disorders. rosa damascena (r. damascena) is a well-known plant suggested to have beneficial effect on gi system. in this study, the effect of aqueous fraction of r. damascena on the contractionsofisolated guinea pig ileum was investigated. materials and methods: aqueous fraction of plant was obta...

The effects of purified scorpion toxin (Tityustoxin or TsTX) were investigated on the isolated guinea-pig and rat ileum, rat spleen strip and hen rectal caecum. The contraction of the ileum was due only in part to the release of acetylcholine, whereas the contraction of the spleen strip and the relaxation of the rectal caecum were due to the release of catecholamines.

The role of Ca(i) and Ca(o) in changes of responsiveness of guinea pig tracheal smooth muscle strips to repeated applications of histamine and acetylcholine was investigated. Homologous desensitization to histamine developed when the airways were exposed to concentrations higher than 10(-5) mol/l, while sensitization to acetylcholine was recorded even when its highest concentration did not exce...

Reactive oxygen species (ROS) are produced in different metabolic processes including the respiratory burst of neutrophils accompanying local inflammation. The aim of this study was to analyze the effects of N-formyl-methionyl-leucyl-phenylalanine (FMLP)-activated neutrophils, isolated from the guinea pig peritoneal cavity, on isolated rings of a large (conduit) artery, the rat thoracic aorta. ...

AIM To find if tacrine exerts a sensitizing effect on the cholinergic receptors of gastric smooth muscles, and study some of the mechanisms inducing it and measure the relative intensity of tacrine's effects on contractile activity. MATERIAL AND METHODS Isometric recording of the mechanical activity of gastric smooth muscle preparations; determination of acetyl-cholinesterase activity in smoo...

To test the hypothesis that vasodilation occurs because of the release of a vasoactive substance after a brief muscle contraction and to determine whether acetylcholine spillover from the motor nerve is involved in contraction-induced hyperemia, tetanic muscle contractions were produced by sciatic nerve stimulation in anesthetized dogs (n = 16), instrumented with flow probes on both external il...