Non-invasive assessment of the cardiac effects of Chironex fleckeri and Carukia barnesi venoms in mice, using pulse wave doppler

Seymour, Jamie; Saggiomo, Silvia L.; Lam, Willis; Pereira, Peter; Little, Mark

doi:10.1016/j.toxicon.2020.06.018

Cited by 4 publications

(9 citation statements)

References 24 publications

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“…Apart from the mode of envenomation, this study replicated the methodology used by Seymour et al [12]. As we reproduced cardiac parameter changes, we contend that we have provided evidence of validity to their parenterally administered methodology and, to a lesser extent, other cubozoan venom methodologies.…”

Section: Discussionsupporting

confidence: 83%

“…This suggests that ventricular contraction was more time-efficient for the same ventricular stroke volume, equating to measurable evidence of increased inotropy in this group. Seymour et al [12] describe similar changes-increases in inotropy and chronotropy with reconstituted CBV, which were promoted as consistent with toxin-induced stress cardiomyopathy from sustained catecholaminergic activity. With this research, we ratify their findings and further refine the position that the measured cardiac decompensation from the C. barnesi venom appears to be due to CBV t alone.…”

Section: Discussionmentioning

confidence: 75%

“…Significantly, there was no accompanying reduction in %IVCT, nominally suggesting no increase in ventricular contraction. As we did not assess aortic valvular flow, we were unable to provide other measures of ventricular contractility such as peak aortic velocity and aortic rise time as described by Seymour [12], which would provide a more complete assessment of systolic function and inotropy. Despite their absence, our findings do not demonstrate any increase in inotropy, suggesting that the improved ventricular relaxation may just be an accompanying necessity of the observed moderate increase in %HR.…”

Section: Discussionmentioning

confidence: 99%

“…Apart from these convenient dermatographic associations, there are no scientific examinations of the difference between bell and tentacle stings, hence our attempt to examine their cardiac effects using pulse wave Doppler in the murine model described by Seymour et al [12]. In their study, reconstituted C. barnesi venom (CBV, mixed tentacular and bell venoms) was parenterally administered to anaesthetised mice.…”

Section: Homotrichous Microbasic Rhopaloids (Type I)mentioning

confidence: 99%

“…When sufficiently anaesthetised as determined by absence of response to firm tail pressure, the mice were weighed (mean: 23.8 g, range: 22.7-25.9 g) and then placed prone on a warmed (37 • C) monitoring mat (Indus Instruments Rodent Surgical Monitor, TX, USA), where ECG and heart rate (HR) were continuously monitored. Using the technique described by Seymour et al [12], a 10 MHz Doppler probe (Indus Instruments Doppler Flow Velocity System, TX, USA) was focused on the mitral valve and Doppler sonograms of blood flow were recorded for analysis. Each sonogram describes the sequentially collected velocities of individual blood cells passing through the aortic valve.…”

Section: Study Micementioning

confidence: 99%

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Differences in Cardiac Effects of Venoms from Tentacles and the Bell of Live Carukia barnesi: Using Non-Invasive Pulse Wave Doppler

Little

Pereira

Seymour

2020

Toxins

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Carukia barnesi was the first in an expanding list of cubozoan jellyfish whose sting was identified as causing Irukandji syndrome. Nematocysts present on both the bell and tentacles are known to produce localised stings, though their individual roles in Irukandji syndrome have remained speculative. This research examines differences through venom profiling and pulse wave Doppler in a murine model. The latter demonstrates marked measurable differences in cardiac parameters. The venom from tentacles (CBVt) resulted in cardiac decompensation and death in all mice at a mean of 40 min (95% CL: ± 11 min), whereas the venom from the bell (CBVb) did not produce any cardiac dysfunction nor death in mice at 60 min post-exposure. This difference is pronounced, and we propose that bell exposure is unlikely to be causative in severe Irukandji syndrome. To date, all previously published cubozoan venom research utilised parenterally administered venom in their animal models, with many acknowledging their questionable applicability to real-world envenomation. Our model used live cubozoans on anaesthetised mice to simulate normal envenomation mechanics and actual expressed venoms. Consequently, we provide validity to the parenteral methodology used by previous cubozoan venom research.

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Section: Discussionsupporting

confidence: 83%

Section: Discussionmentioning

confidence: 75%

Section: Discussionmentioning

confidence: 99%

Section: Homotrichous Microbasic Rhopaloids (Type I)mentioning

confidence: 99%

Section: Study Micementioning

confidence: 99%

See 3 more Smart Citations

Differences in Cardiac Effects of Venoms from Tentacles and the Bell of Live Carukia barnesi: Using Non-Invasive Pulse Wave Doppler

Little

Pereira

Seymour

2020

Toxins

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Inducing metamorphosis in the irukandji jellyfish Carukia barnesi

O'Hara

Seymour

2022

Sci Rep

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Here we utilize chemical ecology as a tool to manipulate the biological system of a small, but highly venomous to humans, cubozoan jellyfish, Carukia barnesi. We trialled a range of chemical reagents including indole compounds, 9-cis-retinoic acid and lugols solution to induce metamorphosis between the polyp and medusa life stages. An optimum method was determined resulting in a 90% metamorphosis rate to healthy medusa by exposing the polyps to 1 μM of 5-methoxy-2-methylindole for 24 h. Of note is that chemical exposure time significantly impacts health and metamorphosis rates in this species. We also present a theoretical mechanism for the chemical/biological interactions occurring during metamorphosis. This is a significant methodological advancement which now enables rearing of this animal en mass in aquaria—a world first for this species—which will subsequently supply and facilitate venom research into this understudied jellyfish.

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Adaptation of a mouse Doppler echocardiograph system for assessing cardiac function and thermal performance in a juvenile salmonid

Muir

Neff

Damjanovski

2021

Conservation Physiology

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Measures of cardiac performance are pertinent to the study of thermal physiology and exercise in teleosts, particularly as they pertain to migration success. Increased heart rate, stroke volume and cardiac output have previously been linked to improved swimming performance and increased upper thermal tolerance in anadromous salmonids. To assess thermal performance in fishes, it has become commonplace to measure the response of maximum heart rate to warming using electrocardiograms. However, electrocardiograms do not provide insight into the hemodynamic characteristics of heart function that can impact whole-animal performance. Doppler echocardiography is a popular tool used to examine live animal processes, including real-time cardiac function. This method allows for nonsurgical measurements of blood flow velocity through the heart and has been used to detect abnormalities in cardiovascular function, particularly in mammals. Here, we show how a mouse Doppler echocardiograph system can be adapted for use in a juvenile salmonid over a range of temperatures and timeframes. Using this compact, noninvasive system, we measured maximum heart rate, atrioventricular (AV) blood flow velocity, the early flow-atrial flow ratio and stroke distance in juvenile Atlantic salmon (Salmo salar) during acute warming. Using histologically determined measures of AV valve area, we show how stroke distance measurements obtained with this system can be used to calculate ventricular inflow volume and approximate cardiac output. Further, we show how this Doppler system can be used to determine cardiorespiratory thresholds for thermal performance, which are increasingly being used to predict the consequences that warming water temperatures will have on migratory fishes.

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Non-invasive assessment of the cardiac effects of Chironex fleckeri and Carukia barnesi venoms in mice, using pulse wave doppler

Cited by 4 publications

References 24 publications

Differences in Cardiac Effects of Venoms from Tentacles and the Bell of Live Carukia barnesi: Using Non-Invasive Pulse Wave Doppler

Differences in Cardiac Effects of Venoms from Tentacles and the Bell of Live Carukia barnesi: Using Non-Invasive Pulse Wave Doppler

Inducing metamorphosis in the irukandji jellyfish Carukia barnesi

Adaptation of a mouse Doppler echocardiograph system for assessing cardiac function and thermal performance in a juvenile salmonid

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