- Title
- Hypotensive and vascular relaxant effects of phospholipase A₂ toxins from Papuan taipan (Oxyuranus scutellatus) venom
- Creator
- Chaisakul, Janeyuth; Isbister, Geoffrey K.; Tare, Marianne; Parkington, Helena C.; Hodgson, Wayne C.
- Relation
- European Journal of Pharmacology Vol. 723, p. 227-233
- Publisher Link
- http://dx.doi.org/10.1016/j.ejphar.2013.11.028
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2014
- Description
- Phospholipase A₂ (PLA₂) toxins are common and abundant components of Australasian elapid venoms. These toxins are associated with a range of activities including neurotoxicity, myotoxicity and coagulation disturbances. We have recently reported that sudden cardiovascular collapse induced by Papuan taipan (Oxyuranus scutellatus) venom involves a combination of the release of dilator autacoids and a direct effect on the smooth muscle. In this study, we aimed to isolate PLA₂ components from Papuan taipan venom and investigate their contribution to the hypotensive action of this venom. O. scutellatus venom was fractionated using size-exclusion high performance liquid chromatography (HPLC), and fractions screened for activity in anaesthetized rats. Fraction three from O. scutellatus venom (i.e. OSC3, 14.2 ± 1.0% of whole venom) produced a 64% decrease in mean arterial pressure. Reverse-phase HPLC indicated that OSC3 consisted of two major components (i.e. OSC3a and OSC3b). OSC3a and OSC3b produced a significant hypotensive response in anaesthetized rats which were attenuated by prior administration of indomethacin or the combination of mepyramine and heparin. N-terminal analysis indicated that OSC3a and b displayed sequence homology to PLA₂ toxins isolated from coastal taipan (O. scutellatus scutellatus) venom. These findings indicate that PLA₂ components may play an important role in the development of hypotension and vascular relaxation which may contribute to the effects observed after envenoming by these Australasian elapids.
- Subject
- vascular relaxation; hypotension; venom; anaesthetized rat; mesenteric artery
- Identifier
- http://hdl.handle.net/1959.13/1045937
- Identifier
- uon:14546
- Identifier
- ISSN:0014-2999
- Language
- eng
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