Actions of some antiarrhythmic agents on heart sarcolemma

Dhalla, Naranjan S.; Harrow, James A.C.; Anand, Madhu

doi:10.1016/0006-2952(78)90464-1

Cited by 30 publications

(5 citation statements)

References 19 publications

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“…It is worth noting that even in histamine-treated rats, the laparotomy- and pylorus ligation-induced pain constitutes a source of stress which contributes to acid secretion through the cholinergic pathway. When histaminergic and cholinergic stimulations of gastric acid secretion were similarly reduced by the aqueous extract of Stachytarpheta cayennensis , it was suggested [40] that the extract could be acting through the inhibition of common steps in both pathways, possibly at the level of histamine release/H 2 -receptor interaction or at the proton pump. In addition, the effects of E. speciosa aqueous extract may not be attributed to a gastric luminal topical activity alone since the extract was also active when administered by intraduodenal route.…”

Section: Discussionmentioning

confidence: 99%

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Antisecretory Action of the Extract of the Aerial Parts ofEremomastax speciosa (Acanthaceae)Occurs through Antihistaminic and Anticholinergic Pathways

Perfusion

Tan

Ernestine

et al. 2014

Advances in Pharmacological Sciences

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Objective. The objective of this study was to find out the possible antiulcer mechanism of action of Eremomastax speciosa. Method. Carbachol- and histamine-induced hypersecretion, associated with the pylorus ligation technique, were used in rats. Gastric mucosal ulceration, mucus production, pH, gastric volume, and acidity were measured. Results. Histamine and carbachol raised gastric acidity to 86.50 and 84.80 mEq/L, respectively, in the control rats, and the extracts (200 mg/kg) reduced gastric acidity to 34.60 and 39.00 mEq/L, respectively. Intraduodenal aqueous extract (400 mg/kg) in histamine- and carbachol-treated rats produced significant (P < 0.001) decreases in acid secretion to 28.50 and 28.80 mEq/L, respectively, and 100 percent inhibition of gastric ulceration. Augmented histamine-induced gastric acid secretion (90.20 mEq/L) was significantly reduced to 52.60 and 27.50 mEq/L by the 200 and 400 mg/kg doses of the aqueous extract, respectively. The extract significantly reduced (P < 0.001) the volume of gastric secretion and significantly increased mucus production. The ulcer inhibition potential of the extract significantly dropped to 25–44% (oral extract) and to 29–37% (duodenal extract) in carbachol/indomethacin-treated rats. Conclusion. The aqueous extract of E. speciosa has both cytoprotective and antisecretory effects. The antisecretory effect may involve a mechanism common to both cholinergic and histaminergic pathways.

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Section: Discussionmentioning

confidence: 99%

“…After laparotomy and pylorus ligation, the extract was introduced into the duodenal lumen using a syringe. The stomach incisions were closed and histamine (2.5 mg/kg) or carbachol (1 mg/kg) were administered 1 h later by subcutaneous route [40]. The animals were sacrificed 4 h after secretagogue administration.…”

Section: Methodsmentioning

confidence: 99%

Antisecretory Action of the Extract of the Aerial Parts ofEremomastax speciosa (Acanthaceae)Occurs through Antihistaminic and Anticholinergic Pathways

Perfusion

Tan

Ernestine

et al. 2014

Advances in Pharmacological Sciences

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“…This effect in depolarized atria and the clearcut 15 positive inotropic effects in normal atria may well be due to the well-documented intracellular actions of quinidine to both inhibit calcium uptake by (Fuchs et al, 1968;Dhalla et al, 1978), and to release calcium from, the sarcoplasmic reticulum (Thorpe, 1973). Thus quinidine may produce two opposing actions, the end-response depending not only on concentration of drug, time of exposure and frequency of stimulation, but also on the absence or presence of both Na' and Ca2" channels and extracellular calcium concentration (also see Kennedy & West, 1960).…”

Section: Electrophysiological Effects In Depolarized Atriamentioning

confidence: 98%

Effects of selective channel blocking agents on contractions and action potentials in K⁺‐depolarized guinea‐pig atria

Brown¹,

Marshall²,

Winslow³

1985

British J Pharmacology

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1 Contractions and transmembrane action potentials were induced by 1 gM isoprenaline in K+-depolarized guinea-pig left atria driven at 0.5 Hz. 2 The stability of these responses was significantly increased by doubling the extracellular glucose concentration to 22 mM. 3 Action potential overshoot increased by 28 mV per ten fold increase in extracellular calcium concentration suggesting that the inward current in this preparation is carried by Ca2+. 4 In depolarized driven preparations, nanomolar concentrations of nifedipine and nisoldipine reduced contractility, maximum rate of depolarization (dV/dt max) and action potential height, whereas the fast channel blocking agents tetrodotoxin and mexiletine (in micromolar concentrations) produced little change. Nifedipine also rendered spontaneously beating depolarized right atrial preparations quiescent. 5 In concentrations which reduced dV/dt of normal action potentials, the sodium channel blocking agents quinidine and Org 6001 reduced the amplitude of contractions and reduced the maximum rate ofphase 0 depolarization (dV/dt) ofaction potentials in depolarized tissue. These actions were reversed by Ca2+ and suggest calcium antagonistic activity. However action potential height was not reduced. Like bepridil, both drugs also reduced the frequency of spontaneous contractions in depolarized right atrial preparations. 6 Unlike Org 6001, quinidine failed to produce a shift in calcium log dose-response curves in driven depolarized preparations and induced positive inotropy in the presence of functional sodium channels. 7 Bepridil inhibited contractions in depolarized atria in the absence ofa reduction in dV/dt suggesting that any calcium antagonistic action in atrial tissue is mainly located at an intracellular site. 8 In conclusion, action potentials elicited by isoprenaline in potassium-depolarized atria bathed in high glucose appear to be Ca2+ mediated. In concentrations which inhibit the inward Na+ current, both quinidine and Org 6001 exhibit calcium channel blocking properties.

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“…Ulcerative lesions were calculated according to the methodology described by Szelenyi and Thiemer [ 61 ]. Indomethacin-induced gastric ulcers in mice according to Rainsford [ 62 ] - In this model, gastric lesions were induced with indomethacin (30 mg/Kg, s.c.) and administered to mice (n=7-8) after a 24 h fast. The AD (250, 500 or 1,000 mg/Kg), cimetidine (100 mg/Kg) or vehicle was administered orally 30 min before the induction of gastric ulcer.…”

Section: Methodsmentioning

confidence: 99%

Polyphenols with Antiulcerogenic Action from Aqueous Decoction of Mango Leaves (Mangifera indica L.)

et al. 2009

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This study was designed to determine the gastroprotective effect of a Mangifera indica leaf decoction (AD), on different experimental models in rodents. The administration of AD up to a dose of 5 g/kg (p.o.) did not produce any signs or symptoms of toxicity in the treated animals, while significantly decreasing the severity of gastric damage induced by several gastroprotective models. Oral pre-treatment with AD (250, 500 or 1000 mg/kg) in mice and rats with gastric lesions induced by HCl/ethanol, absolute ethanol, non-steroidal anti-inflammatory drug (NSAID) or stress-induced gastric lesions resulted in a significant decrease of said lesions. Phytochemical analyses of AD composition demonstrated the presence of bioactive phenolic compounds that represent 57.3% of total phenolic content in this extract. Two main phenolic compounds were isolated, specifically mangiferin (C-glucopyranoside of 1,3,6,7-tetrahydroxyxanthone) and C-glucosyl-benzophenone (3-C-β-D-glucopyranosyl-4’,2,4,6-tetrahydroxybenzophenone). These findings indicate the potential gastroprotective properties of aqueous decoction from M. indica leaves.

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Actions of some antiarrhythmic agents on heart sarcolemma

Cited by 30 publications

References 19 publications

Antisecretory Action of the Extract of the Aerial Parts ofEremomastax speciosa (Acanthaceae)Occurs through Antihistaminic and Anticholinergic Pathways

Antisecretory Action of the Extract of the Aerial Parts ofEremomastax speciosa (Acanthaceae)Occurs through Antihistaminic and Anticholinergic Pathways

Effects of selective channel blocking agents on contractions and action potentials in K⁺‐depolarized guinea‐pig atria

Polyphenols with Antiulcerogenic Action from Aqueous Decoction of Mango Leaves (Mangifera indica L.)

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Actions of some antiarrhythmic agents on heart sarcolemma

Cited by 30 publications

References 19 publications

Antisecretory Action of the Extract of the Aerial Parts ofEremomastax speciosa (Acanthaceae)Occurs through Antihistaminic and Anticholinergic Pathways

Antisecretory Action of the Extract of the Aerial Parts ofEremomastax speciosa (Acanthaceae)Occurs through Antihistaminic and Anticholinergic Pathways

Effects of selective channel blocking agents on contractions and action potentials in K+‐depolarized guinea‐pig atria

Polyphenols with Antiulcerogenic Action from Aqueous Decoction of Mango Leaves (Mangifera indica L.)

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Product

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Effects of selective channel blocking agents on contractions and action potentials in K⁺‐depolarized guinea‐pig atria