A pharmacological examination of the cardiovascular effects of Malayan Krait (Bungarus candidus) venoms

Chaisakul, Janeyuth and Ahmad Rusmili, Muhamad Rusdi and Hodgson, Wayne C. and Hatthachote, Panadda and Suwan, Kijja and Inchan, Anjaree and Chanhome, Lawan and Othman, Iekhsan and Chootip, Krongkarn (2017) A pharmacological examination of the cardiovascular effects of Malayan Krait (Bungarus candidus) venoms. Toxins, 9 (4). pp. 1-11. ISSN 2072-6651

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Abstract

Cardiovascular effects (e.g., tachycardia, hypo- and/or hypertension) are often clinical outcomes of snake envenoming. Malayan krait (Bungarus candidus) envenoming has been reported to cause cardiovascular effects that may be related to abnormalities in parasympathetic activity. However, the exact mechanism for this effect has yet to be determined. In the present study, we investigated the in vivo and in vitro cardiovascular effects of B. candidus venoms from Southern (BC-S) and Northeastern (BC-NE) Thailand. SDS-PAGE analysis of venoms showed some differences in the protein profile of the venoms. B. candidus venoms (50 µg/kg–100 µg/kg, i.v.) caused dose-dependent hypotension in anaesthetised rats. The highest dose caused sudden hypotension (phase I) followed by a return of mean arterial pressure to baseline levels and a decrease in heart rate with transient hypertension (phase II) prior to a small decrease in blood pressure (phase III). Prior administration of monovalent antivenom significantly attenuated the hypotension induced by venoms (100 µg/kg, i.v.). The sudden hypotensive effect of BC-NE venom was abolished by prior administration of hexamethonium (10 mg/kg, i.v.) or atropine (5 mg/kg, i.v.). BC-S and BC-NE venoms (0.1 µg/kg–100 µg/ml) induced concentration-dependent relaxation (EC50 = 8 ± 1 and 13 ± 3 µg/mL, respectively) in endothelium-intact aorta. The concentration–response curves were markedly shifted to the right by pre-incubation with L-NAME (0.2 mM), or removal of the endothelium, suggesting that endothelium-derived nitric oxide (NO) is likely to be responsible for venom-induced aortic relaxation. Our data indicate that the cardiovascular effects caused by B. candidus venoms may be due to a combination of vascular mediators (i.e., NO) and autonomic adaptation via nicotinic and muscarinic acetylcholine receptors

Item Type:	Article (Journal)
Additional Information:	5591/56289
Uncontrolled Keywords:	venom; Malayan krait; cardiovascular; rat; hypotension
Subjects:	Q Science > QL Zoology R Medicine > RM Therapeutics. Pharmacology R Medicine > RM Therapeutics. Pharmacology > RM300 Drugs and their action R Medicine > RS Pharmacy and materia medica
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Pharmacy > Department of Basic Medical Sciences
Depositing User:	Dr Muhamad Rusdi Ahmad Rusmili
Date Deposited:	17 Apr 2017 15:07
Last Modified:	14 Mar 2018 19:00
URI:	http://irep.iium.edu.my/id/eprint/56289

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