Cardiorespiratory effects of brevetoxin (PbTx-2) in conscious, tethered rats

Templeton, C. B.; Poli, Mark; LeClaire, Ross D.

doi:10.1016/0041-0101(89)90155-4

Cited by 27 publications

(12 citation statements)

References 7 publications

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“…The effects of each respective toxin on heart rate in fish embryos are complicated due to the nature of a developmental model being used in vivo. Cardiovascular responses to brevetoxins have been observed in rats, cats, and dogs thus far, but very few aquatic models, and no marine models, have been tested (Borison et al 1985;Edmunds et al 1999;Johnson et al 1985;Kimm-Brinson and Ramsdell 2001;Templeton et al 1989). The results of these mammalian studies suggest that brevetoxins elicit a Bezold-Jarisch effect in which delayed bradycardia is observed (Johnson et al 1985;Poli et al 1990).…”

Section: Discussionmentioning

confidence: 64%

The type B brevetoxin (PbTx-3) adversely affects development, cardiovascular function, and survival in Medaka (Oryzias latipes) embryos.

Colman

Ramsdell

2003

Environ Health Perspect

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Brevetoxins are produced by the red tide dinoflagellate Karenia brevis. The toxins are lipophilic polyether toxins that elicit a myriad of effects depending on the route of exposure and the target organism. Brevetoxins are therefore broadly toxic to marine and estuarine animals. By mimicking the maternal route of exposure to the oocytes in finfish, we characterized the adverse effects of the type B brevetoxin brevetoxin-3 (PbTx-3) on embryonic fish development and survival. The Japanese rice fish, medaka (Oryzias latipes), was used as the experimental model in which individual eggs were exposed via microinjection to various known concentrations of PbTx-3 dissolved in an oil vehicle. Embryos injected with doses exceeding 1.0 ng/egg displayed tachycardia, hyperkinetic twitches in the form of sustained convulsions, spinal curvature, clumping of the erythrocytes, and decreased hatching success. Furthermore, fish dosed with toxin were often unable to hatch in the classic tail-first fashion and emerged head first, which resulted in partial hatches and death. We determined that the LD 50 (dose that is lethal to 50% of the fish) for an injected dose of PbTx-3 is 4.0 ng/egg. The results of this study complement previous studies of the developmental toxicity of the type A brevetoxin brevetoxin-1 (PbTx-1), by illustrating in vivo the differing affinities of the two congeners for cardiac sodium channels. Consequently, we observed differing cardiovascular responses in the embryos, wherein embryos exposed to PbTx-3 exhibited persistent tachycardia, whereas embryos exposed to PbTx-1 displayed bradycardia, the onset of which was delayed.

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Section: Discussionmentioning

confidence: 64%

The type B brevetoxin (PbTx-3) adversely affects development, cardiovascular function, and survival in Medaka (Oryzias latipes) embryos.

Colman

Ramsdell

2003

Environ Health Perspect

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“…Both brevetoxins and ciguatoxins bind to sodium channel site 5 to shift activation to more negative potentials, resulting in subsequent membrane depolarisation (Huang et al, 1984;Catterall, 1985;Poli et al, 1986;Lombet et al, 1987). The effects and toxicokinetics of brevetoxins in mammaDownloaded by [McGill University Library] at 17:34 04 October 2012 lian models (Templeton et al, 1989;Cattet and Geraci, 1993) and the chemistry, pharmacology, and toxicology of brevetoxins in experimental systems (see Baden, 1983Baden, , 1989) have been studied. Mice administered brevetoxins i.p.…”

Section: Brevetoxinsmentioning

confidence: 97%

The Effects of Harmful Algal Blooms on Aquatic Organisms

Landsberg

2002

Reviews in Fisheries Science

1,135

807

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“…(Atchison, Luke, Narahashi, & Vogel, 1986;Trainer, Moreau, Guedin, Baden, & Catterall, 1993). These effects lead to rapid reductions in respiratory rate, cardiac rhythm alterations, and hypothermia (Templeton, Poli, & LeClaire, 1989).…”

Section: Domoic Acidmentioning

confidence: 99%

Derivation of toxicity equivalency factors for marine biotoxins associated with Bivalve Molluscs

Botana

Heß

Munday

et al. 2017

Trends in Food Science & Technology

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Background Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory limits are set to ensure that commercially available seafood is not contaminated with unsafe levels. Scope and Approach The mouse bioassay was used to measure the toxicity in seafood extracts to determine if a sample exceeded regulatory limits. The advantage of this approach was to provide an estimation of the total toxicity in the sample. As instrumental methods of analysis advance and serve as replacements to the mouse bioassay, the challenge is translating individual toxin concentrations into toxicity to determine whether regulatory limits have been exceeded. Such analyses provide accurate quantitation of the toxin Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site. analogues, by they have widely dissimilar potencies. Thus, knowledge of the relative toxicities is required for risk assessment and determining overall toxicity. The ratios between the toxicity of the analogues and that of a reference compound within the same toxin group are termed "Toxicity Equivalency Factors" (TEFs). Key Findings and Conclusions In this document, the requirements for determining TEFs of toxin analogues are described, and recommendations for research to further refine TEFs are identified. The proposed TEFs herein, when applied to toxin analogue concentrations determined using analytical methods, will provide a base to determine overall toxicity, thereby protecting human health. Highlights ► Marine toxins TEF are revised according to recent toxicology studies. ► TEF for each toxin group are proposed. ► The proposed TEF were agreed by a joint FAO-WHO working group.

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Cardiorespiratory effects of brevetoxin (PbTx-2) in conscious, tethered rats

Cited by 27 publications

References 7 publications

The type B brevetoxin (PbTx-3) adversely affects development, cardiovascular function, and survival in Medaka (Oryzias latipes) embryos.

The type B brevetoxin (PbTx-3) adversely affects development, cardiovascular function, and survival in Medaka (Oryzias latipes) embryos.

The Effects of Harmful Algal Blooms on Aquatic Organisms

Derivation of toxicity equivalency factors for marine biotoxins associated with Bivalve Molluscs

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