The role of propranolol and atropine in mitigating the toxic effects of scorpion venom on rat electrocardiogram

Omran, Mohamed A.; Abdel‐Rahman, Mohamed S.; Nabil, Zohour I.

doi:10.1016/0378-4274(92)90144-9

Cited by 8 publications

(4 citation statements)

References 19 publications

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“…So, the neurotransmitter-independent decrease in heart rate appears to be a direct effect of the venom on the myocardium. The same results were obtained by Omran et al (1992b) with the venom of L. quinquestriatus. They found that application of atropine before the injection of L. quinquestriatus venom has no role to prevent bradycardia induced by scorpion venom.…”

Section: Discussionsupporting

confidence: 89%

Cardiac disorders and mode of action of the Egyptian scorpion venom Androctonus bicolor on isolated toad’s heart

Abdel-Rahman

Ayed

Abdel–Mottaleb

et al. 2015

The Journal of Basic & Applied Zoology

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Scorpion venom is a complex mixture of components with various pharmacological and toxicological effects. It is characterized by the presence of a large number of toxins that specifically interact with ion channels of excitable cells. The Egyptian scorpion Androctonus bicolor belongs to the family of Buthidae and until now no information is available about the effect of its venom on cardiac muscles. Using an in vitro approach, cardiotoxicity and mode of action of A. bicolor venom on isolated toad's heart were investigated. Direct application of scorpion venom (0.5 lg/ml) into isolated toad's heart induced a remarkable bradycardia concomitant with a protraction in the conduction time (P-R interval). In the meantime, a significant increase in the R-wave amplitude (ventricular contraction) was noticed after 5 min of venom perfusion. Various cases of cardiac disorders were recorded such as sinus arrhythmias, ectopic beats and different degrees of heart block. Through using different autonomic and ion channel blockers, the possible mechanism of action of A. bicolor venom on isolated toad's heart was revealed. The application of both atropine (4 lg/ml) and verapamil (5 lg/ml) could not alleviate the pronounced negative chronotropic and positive inotropic effects. Meanwhile, a significant decrease in the R-wave amplitude was observed after propranolol (5 lg/ml) application. In conclusion, our findings indicate that the venom of A. bicolor directly influenced the cardiac electrical activity of toads through b-adrenergic receptors. The direct effect of this venom on cardiac tissues may significantly contribute in the development of several cardiotoxic effects following scorpion sting.

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Section: Discussionsupporting

confidence: 89%

Cardiac disorders and mode of action of the Egyptian scorpion venom Androctonus bicolor on isolated toad’s heart

Abdel-Rahman

Ayed

Abdel–Mottaleb

et al. 2015

The Journal of Basic & Applied Zoology

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“…Success of the combined Lidocaine and Atropin treatment indicates a possible involvement of the autonomous nervous system. Present findings indicate an increase in the parasympathetic tone [38] but, not in the sympathetic tone [28]. However, it should be emphasised that LqV has a potency to evoke cardio‐toxic effects by its direct action in myocardial cells ( and ).…”

Section: Discussionmentioning

confidence: 81%

“…The causes of the changes observed in ECG could be discussed on the basis of the findings from isolated preparations. However, it should be noted that additional effects by LqV in haemodynamic factors [2] and autonomous nervous tone [28,38] should be involved in the ECG changes. The increase in the QRS complex duration is most probably due to an increase in the duration of the APs from the ventricular myocytes.…”

Section: Discussionmentioning

confidence: 99%

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Lidocaine diminishes arrhythmia by Leiurus quinquestriatus quinquestriatus venom in rats

Puralı¹,

Yağcıoğlu²

2002

Fundamemntal Clinical Pharma

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The venom from the scorpion Leiurus quinquestriatus quinquestriatus has previously been shown to alter the excitability of the neural and skeletal muscle preparations. The present study was undertaken to explore the effects of the venom in cardiac potential signals at the animal, tissue and the cell level in rats hearts. In anaesthetised animals Leiurus quinquestriatus quinquestriatus venom (LqV) 100 microg applied intravenously reduced the heart rate by 13%, and evoked some abnormal waveforms in the electrocardiogram (ECG). Lidocaine injection (0.02 microg) restored the waveform of the ECG. However, the sinus rhythm resumed only when Atropine (2.5 microg) was applied in addition to previously administered Lidocaine. In isolated atria, LqV (10-2 mg/mL) exposure abolished the sinus rhythm and decreased the spontaneous rate by 38%, and increased the contraction amplitude by 85%, and duration of the contractions by 17%. The gross electrical activity of the preparation and the duration of the individual atrial muscle action potential were prolonged by 150% and 186%, respectively. In isolated papillary muscle, LqV evoked irregular contractions, and the duration of the action potential was increased about 15-fold. The effects by LqV in the action potential were present when calcium channels were blocked but not when extracellular sodium was substituted. Lidocaine (75 nM) antagonised the effects by LqV in isolated atria and papillary muscle. It was concluded that the lethal cardio-toxic effects by LqV were mainly due to its direct action in myocardial cells, and partly to an alteration in the autonomous nervous activity.

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Use of dantrolene in experimental scorpion envenomation by Androctonus Australis Hector

et al. 1995

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Hyperthermia and profuse perspiration are rarely absent in severe cases of scorpion envenomation. Based on these observations, the aim of this study was to determine the therapeutic effects of dantrolene, on experimental poisoning by the venom of Androctonus australis hector. Dantrolene is a directly acting muscle relaxant which lowers the body temperature in malignant hyperthermia. The results indicate that the early use of this drug raises the LD50 in experimentally poisoned mice. If these results are transposable to humans, dantrolene could be a useful therapeutic adjuvant.

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The role of propranolol and atropine in mitigating the toxic effects of scorpion venom on rat electrocardiogram

Cited by 8 publications

References 19 publications

Cardiac disorders and mode of action of the Egyptian scorpion venom Androctonus bicolor on isolated toad’s heart

Cardiac disorders and mode of action of the Egyptian scorpion venom Androctonus bicolor on isolated toad’s heart

Lidocaine diminishes arrhythmia by Leiurus quinquestriatus quinquestriatus venom in rats

Use of dantrolene in experimental scorpion envenomation by Androctonus Australis Hector

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