Mechanism of Action of Muscarine on the Longitudinal Muscle of the Guinea‐pig Isolated Ileum

Ochillo, Richard F.; Tsai, Chien‐Sung; Tsai, Mei H.

doi:10.1111/j.1476-5381.1981.tb09117.x

Cited by 14 publications

(3 citation statements)

References 19 publications

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“…The present study validates the findings of Lurie et al 66 that the poisonings by Inocybe species is associated with constriction of pupils, muscle spasms, diarrhoea, slowing of heartbeat and a drop in blood pressure. In a study carried out by Ochillo et al 67 , it was demonstrated that muscarine elicited a contraction of ileal longitudinal muscles. This could possibly explain the increase in defecation (Fig.…”

Section: Effect Of In Vitro Digestion On Muscarinementioning

confidence: 96%

Toxic metabolite profiling of Inocybe virosa

Latha

Naveen

Naika

et al. 2020

Sci Rep

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Wild mushroom foraging involves a high risk of unintentional consumption of poisonous mushrooms which is a serious health concern. This problem arises due to the close morphological resemblances of toxic mushrooms with edible ones. The genus Inocybe comprises both edible and poisonous species and it is therefore important to differentiate them. Knowledge about their chemical nature will unambiguously determine their edibility and aid in an effective treatment in case of poisonings. In the present study, the presence of volatile toxic metabolites was verified in Inocybe virosa by gas chromatography. Methyl palmitate, phenol, 3,5-bis (1,1-dimethyl ethyl) and phytol were the identified compounds with suspected toxicity. The presence of the toxin muscarine was confirmed by liquid chromatography. The in vitro study showed that there was negligible effect of the digestion process on muscarine content or its toxicity. Therefore, the role of muscarine in the toxicity of Inocybe virosa was studied using a bioassay wherein metameters such as hypersalivation, immobility, excessive defecation, heart rate and micturition were measured. Administration of muscarine resulted in an earlier onset of symptoms and the extract showed a slightly stronger muscarinic effect in comparison to an equivalent dose of muscarine estimated in it. Further, the biological fate of muscarine was studied by pharmacokinetics and gamma scintigraphy in New Zealand white rabbits. Significant amount of the toxin was rapidly and effectively concentrated in the thorax and head region. This study closely explains the early muscarinic response such as miosis and salivation in mice. By the end of 24 h, a relatively major proportion of muscarine administered was accumulated in the liver which stands as an explanation to the hepatotoxicity of Inocybe virosa. This is one of the rare studies that has attempted to understand the toxic potential of muscarine which has previously been explored extensively for its pharmaceutical applications. Wild mushroom foraging involves a high risk of unintentional consumption of poisonous mushrooms which is a serious health concern. This problem arises due to the close morphological resemblance of toxic mushrooms with edible ones. The genus Inocybe also comprises both edible and poisonous species and it is therefore important to differentiate them. The species Inocybe virosa which is the focus of the present study is closely allied to Inocybe cutifracta which is an edible mushroom. The taxonomic classification of a mushroom species under the genus Inocybe, generally raises a suspicion about its edibility. This inevitable caution stems from the literature which abounds in cases of poisonings due to Inocybe mushrooms. Some of the poisonings reported have been associated with Inocybe fastigiata 1,2 , I. tristis 3 , I. anterospora 4 , I. aeruginascens 5 and I. patouillardii 6. Species such as I. asterospora, I. gobeyi, I. napipes, I. repanda, I. radiata, I. rimosa show psychotropic effects and classified as neurotoxic. Most of the I...

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Section: Effect Of In Vitro Digestion On Muscarinementioning

confidence: 96%

Toxic metabolite profiling of Inocybe virosa

Latha

Naveen

Naika

et al. 2020

Sci Rep

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“…The A subunit has 120 amino acids and the B subunit has 60 amino acids giving a combined molecular weight of 21,800 Da (Rowan, 2001). Blockage of muscarinic receptors by b-B has been reported by Ochillo et al (1981).…”

Section: Choice Of Bungarotoxinsmentioning

confidence: 96%

Identification of Acetylcholinesterase Receptors in Rotifera

et al. 2005

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We have identified acetylcholinesterase (AChE) receptors in six freshwater rotifers. Using b-bungarotoxin labelled with fluoresceinisothiocyanate (FITC), muscarinic and nicotinic receptors were found in Brachionus quadridentatus (females and males), Lecane luna, Lecane quadridentata, Plationus patulus, and Rotaria neptunia. Using a-bungarotoxin-FITC, nicotinic receptors were identified in B. quadridentatus, Lecane bulla, L. luna, L. quadridentata, P. patulus and R. neptunia. Concentrations as low as 1.5 nM of b-bungarotoxin, and 5 nM of a-bungarotoxin identified receptors in the digestive tract. Higher concentrations of both toxins identified additional receptors associated with the lorica. A preliminary analysis of fluorescence intensity in L. quadridentata showed that response to a-bungarotoxin increases with age from newborn to 48-h old, but not in older individuals, thus suggesting an increase in binding sites, and possibly in number of nicotinic receptors, during the first 48-h of life. Our study extends the number of rotifer species in which AChE receptors have been reported.

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“…The experiment was performed to assess the effect of LP extract on ileum contraction using isolated ileum of guinea pig [9]. Male guinea pig was killed and the ileum was rapidly removed and transferred to a dish containing Tyrode's solution aerated with 95% O 2 and 5% CO 2 , at 37°C.…”

Section: Bioassay Of Cholinergic Activity Of Lp Extracts Using Isolated Guinea Pig Ileummentioning

confidence: 99%

Luem Pua Rice Extract Attenuates the Severity of Dextran Sulfate Sodiuminduced Ulcerative Colitis in Rats Through Cholinomimetic Effects

Thipart¹,

Phunikhom

Noenplab

et al. 2021

Int J App Pharm

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Objective: The objective of the study was to investigate the effect of aqueous extract of unpolished dark purple glutinous Thai rice variety Luem Pua(LP) in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in rat and the possible cholinomimetic effects of the extract.Methods: The effect of LP extract (0.5, 1, or 1.5 mg/ml final concentration) on ileum contraction was tested using isolated guinea pig ileum. Certainagonists (acetylcholine, tetramethylammonium, and clonidine) and antagonists (hexamethonium chloride and atropine) were studied to determinethe cholinomimetic effect of the extract. The effects of LP extract (5 g/kg/day) in DSS-induced UC model (drinking water was replaced with 3%DSS in water for 7 days) in rat were evaluated. On each day of treatment, the change of disease activity index (DAI) was recorded. At the end of theexperiments, rats were terminated and disease severity expressed as DAI, colon length, and spleen weight were determined.Results: LP extract at the concentration of 0.5, 1, and 1.5 mg/ml (final concentration) could contract the ileum in a dose-dependent manner and beblocked completely by atropine. Oral administration of LP extract could significantly attenuate the severity of DSS-induced UC as seen by the reductionof DAI, colon length, and spleen weight.Conclusion: Results in isolated guinea pig ileum suggest that LP might contain active substance that could activate muscarinic receptors. In additionto antioxidant activity, through activation of muscarinic receptor, might explain the protective effects of LP extract against DSS-induced UC in rats.

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Mechanism of Action of Muscarine on the Longitudinal Muscle of the Guinea‐pig Isolated Ileum

Cited by 14 publications

References 19 publications

Toxic metabolite profiling of Inocybe virosa

Toxic metabolite profiling of Inocybe virosa

Identification of Acetylcholinesterase Receptors in Rotifera

Luem Pua Rice Extract Attenuates the Severity of Dextran Sulfate Sodiuminduced Ulcerative Colitis in Rats Through Cholinomimetic Effects

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