Search results for "Holy"
showing 10 items of 150 documents
Relaxant activity of three aporphine alkaloids from Annona cherimolia on isolated aorta of rat.
1995
Abstract In the present study we tested the relaxant effect of three aporphine alkaloids—roemerine, anonaine and dehydroroemerine—isolated from the roots of Annona cherimolia, on isolated strips of rat thoracic aorta. All compounds completely relaxed KCl- and noradrenaline-induced contractions with different potencies depending on their structural characteristics. The experiments, carried out in Ca2+-free medium using two different agonists (noradrenaline and caffeine) which mobilize calcium intracellularly by different mechanisms of action, showed that the alkaloids made no contribution to intracellular calcium processes. The present study provides evidence that the relaxant effects produc…
Effects of menthol on circular smooth muscle of human colon: Analysis of the mechanism of action.
2014
Abstract Menthol is the major constituent of peppermint oil, an herbal preparation commonly used to treat nausea, spasms during colonoscopy and irritable bowel disease. The mechanism responsible for its spasmolytic action remains unclear. The aims of this study were to investigate the effects induced by menthol on the human distal colon mechanical activity in vitro and to analyze the mechanism of action. The spontaneous or evoked-contractions of the circular smooth muscle were recorded using vertical organ bath. Menthol (0.1 mM–30 mM) reduced, in a concentration-dependent manner, the amplitude of the spontaneous contractions without affecting the frequency and the resting basal tone. The in…
Spasmolytic Effects of Aphanizomenon Flos Aquae (AFA) Extract on the Human Colon Contractility.
2021
The blue-green algae Aphanizomenon flos aquae (AFA), rich in beneficial nutrients, exerts various beneficial effects, acting in different organs including the gut. Klamin® is an AFA extract particularly rich in β-PEA, a trace-amine considered a neuromodulator in the central nervous system. To date, it is not clear if β-PEA exerts a role in the enteric nervous system. The aims of the present study were to investigate the effects induced by Klamin® on the human distal colon mechanical activity, to analyze the mechanism of action, and to verify a β-PEA involvement. The organ bath technique, RT-PCR, and immunohistochemistry (IHC) were used. Klamin® reduced, in a concentration-dependent manner, …
Prejunctional M1 and postjunctional M3 muscarinic receptors in the circular muscle of the guinea-pig ileum.
1995
The effects of subtype-selective muscarinic receptor antagonists on electrically evoked release of acetylcholine and muscle contraction were compared in circular muscle preparations of the guinea-pig ileum. Incubation of the preparation with [3H]choline resulted in the formation of [3H]acetylcholine. Electrical stimulation caused the release of [3H]acetylcholine which was abolished by tetrodotoxin and omission of calcium from the medium. 5-Hydroxytryptamine (10 microM) and the nicotinic agonist 1,1-dimethyl-4-phenyl-piperazinium (300 microM) did not change acetylcholine release. The muscarinic antagonists pirenzepine (M1 selective), AF-DX 116 (M2 selective) and hexahydrosiladifenidol (M3 se…
Nicotinic and muscarinic modulation of 5-hydroxytryptamine (5-HT) release from porcine and canine small intestine
1992
Strips of porcine and canine small intestine were incubated in vitro and the release of 5-hydroxytryptamine (5-HT) was determined by HPLC with electrochemical detection. The spontaneous outflow of 5-HT from the porcine and canine small intestine largely reflects calcium-dependent 5-HT secretion from enterochromaffin cells which are under a spontaneous neuronal, excitatory input as indicated by the inhibitory effect (30-40%) of tetrodotoxin. In both species, nicotine enhanced the release of 5-HT in a concentration-dependent manner by a maximum of about 50% at 100 microM. This effect was blocked by the nicotine receptor antagonist hexamethonium, but not by the subtype-selective nicotine recep…
Muscarinic Control of Histamine Release from Airways
2000
Isolated human bronchi and rat tracheae were incubated in organ baths to measure histamine release. The calcium ionophore A23187, 3 micromol/L in rat trachea and 10 micromol/L in human bronchi, stimulated histamine release by 145 +/- 50% (n = 6) and 270 +/- 48% (n = 7) above the prestimulation level, respectively. Acetylcholine (100 pmol/L; human bronchi) or oxotremorine (1, 100, 10,000 nmol/L; rat trachea) did not affect the spontaneous histamine release. In rat tracheae neither acetylcholine nor oxotremorine inhibited A23187-evoked histamine release, whereas 100 pmol/L acetylcholine significantly suppressed the evoked histamine release in human bronchi by 86%. For receptor characterizatio…
The effect of S-(+)-boldine on the α1-adrenoceptor of the guinea-pig aorta
1996
1. The cardiovascular activity of S-(+)-boldine, an aporphine alkaloid structurally related to papaverine, was determined. The work includes functional studies on guinea-pig isolated aorta contracted with noradrenaline, caffeine, KCl or Ca2+, and on guinea-pig trachea contracted with acetylcholine or histamine. 2. S-(+)-boldine inhibited in a concentration-dependent manner the contractile response evoked by noradrenaline (10 microM) in guinea-pig aorta (IC50 = 1.4 +/- 0.2 microM) while the KCl depolarizing solution (60 mM)- or the Ca2+ (1 mM)-induced contractions were only partially affected by boldine up to 300 microM. In contrast, papaverine relaxed noradrenaline (NA), KCl or Ca2+ induced…
Different muscarinic receptors mediate autoinhibition of acetylcholine release and vagally-induced vasoconstriction in the rat isolated perfused heart
1990
Experiments were carried out on rat isolated perfused hearts with both vagus nerves attached. The acetylcholine stores were labelled with [14C]-choline. The effects of muscarinic receptor antagonists on the [14C]-overflow and increase in perfusion pressure evoked by vagus nerve stimulation (10 Hz, 4-10 mA) were studied in order to determine the muscarinic receptor type involved in autoinhibition of acetylcholine release and vagally-induced vasoconstriction in the rat heart. Stimulation of the vagus nerves (1200 pulses) caused an increase in [14C]-overflow and in perfusion pressure which was significantly reduced by hexamethonium 500 mumol/l and abolished by tetrodotoxin 0.3 mumol/l or perfu…
Differentiation of calcium antagonists with respect to their effects in normal and skinned taenia caeci preparations
1987
Abstract In taenia preparations, depolarized by a K+-rich medium, Ca2+ caused contraction and cinnarizine (0.4–100 μM), trifluoperazine (2–100 μM) and verapamil (0.02–10 μM) caused concentration-dependent antagonism of Ca2+, displacing the Ca2+ log concentration-effect curve to the right and depressing the maximal response. Equieffective (IC75) antispasmogenic concentrations were selected. The antispasmogenic effects of verapamil were readily offset by removing the drug from the bathing fluid but those of the other drugs were not. The calcium antagonists (antispasmogenic IC75) were then tested for spasmolytic activity in tissues generating tension in response to the EC80 of Ca2+. Verapamil …
Effects of Intraaccumbens Microinjections of Quinpirole on Head Turning and Circling Movement in the Rat
1998
This study was designed to evaluate whether nucleus accumbens dopamine D2 receptors are involved in the initiation of the movement, as distinguished from its execution. For this purpose, the effects of the quinpirole-induced increase of nucleus accumbens dopamine D2 receptor activity were observed on specific parameters of the circling behavior and of its first stage, the head-turning (HT) movement. The experiments were performed on rats with unilateral 6-hydroxydopamine (6-OHDA) lesion of the pars compacta of the substantia nigra and d-amphetamine i.p. (3 mg/kg). Bilateral intraaccumbens microinjections of quinpirole (1, 5, and 10 microg/0.5 microl), an agonist of the D2 receptor family, w…