Medicinal Afflictions and Treatment

DWhatley

Cthulhu
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#1
A recent paper on the testing of anesthetics on octopuses let me to start a thread to collect the rare bits of medical information that is available. To start, I added the anesthetics paper and will attempt to locate and link some of the threads discussing the use of antibiotics for infection.

Please add new information as you find it.
 

DWhatley

Cthulhu
Staff member
Moderator
#2
Safe Anaesthetics

The effects of prospective anaesthetic substances on cephalopods: Summary of original data and a brief review of studies over the last two decades Ian G. Gleadall Journal of Experimental Marine Biology and Ecology - March 2013

Absract (article is subscription or individual purchase):

Trials were performed with magnesium chloride, ethanol and eight more complex organic substances screened for their effect as immersion anaesthetics for small, medium and large octopus species commonly used as experimental animals in Japan: Amphioctopus fangsiao, Octopus vulgaris, and Enteroctopus dofleini, respectively. Four of the organics were synthetic compounds commonly used as fish anaesthetics (metomidate, MS-222, propoxate, and quinaldine sulphate) and four have been used on other invertebrates (chloretone, gallamine, phenoxetol, and nicotine sulphate). Urethane (no longer used because of its carcinogenic properties) was used as a reference anaesthetic because of its long history of success with octopuses. Best results for anaesthetic effect were obtained with magnesium chloride and ethanol (which mimicked the typical anaesthetic effects seen with urethane) although some resistance to full anaesthesia was observed with ethanol when water temperatures were 10 °C or below in winter. No successful anaesthetic effects were obtained with the fish anaesthetics: in particular, metomidate was toxic even at low concentrations. Similarly (at the temperatures tested), chloretone, nicotine sulphate and phenoxetol were ineffective as anaesthetics and had toxic effects. Substances used to date as anaesthetics for cephalopods are briefly reviewed and it is concluded that future investigations to improve the provision of stable, safe and reliable anaesthesia for cephalopods would probably benefit from combinations of higher doses for shorter exposure times, and the co-administration of two or more substances. Empirical testing is still required for application to different species and to define appropriate concentrations, temperature and pH ranges.
 

DWhatley

Cthulhu
Staff member
Moderator
#3
Video: How to anesthetize an octopus Agata Blaszczak-Boxe 2014

When it comes to lab animal welfare, rats and mice aren’t the only creatures of concern. In 2013, the European Union mandated that cephalopods—a group that includes octopuses and squid—be treated humanely when used for scientific research. In response, researchers have figured out how to anesthetize octopuses so the animals do not feel pain while being transported and handled during scientific experiments, for instance those examining their behavior, physiology, and neurobiology, as well as their use in aquaculture. In a study published online this month in the Journal of Aquatic Animal Health, researchers report immersing 10 specimens of the common octopus (Octopus vulgaris) in seawater with isoflurane, an anesthetic used in humans. They gradually increased the concentration of the substance from 0.5% to 2%. The investigators found that the animals lost the ability to respond to touch and their color paled, which means that their normal motor coordination of color regulation by the brain was lost, concluding that the animals were indeed anesthetized. The octopuses then recovered from the anesthesia within 40 to 60 minutes of being immersed in fresh seawater without the anesthetic, as they were able to respond to touch again and their color was back to normal. The researchers captured the anesthetization process on video, shown above [in the linked reference].
 

DWhatley

Cthulhu
Staff member
Moderator
#4
Effect of different formulations of magnesium chloride used as anaesthetic agent on the performance of the isolated heart of Octopus vulgaris
Chiara Pugliese, Rosa Mazza, Paul L. Andrews, Maria C. Cerra, Graziano Fiorito, Alfonsina Gattuso 2016 (provisional pdf available at Frontiers in Physiology link)

Magnesium chloride (MgCl2) is commonly used as a general anaesthetic in cephalopods, but its physiological effects including those at cardiac level are not well characterised. We used an in vitro isolated perfused systemic heart preparation from the common octopus, Octopus vulgaris, to investigate: a) if in vivo exposure to MgCl2 formulations had an effect on cardiac function in vitro and, if so, could this impact recovery from anaesthesia; b) direct effects of MgCl2 formulations on cardiac function. In vitro hearts removed from animals exposed in vivo to 3.5% MgCl2 in sea water (20min) or to a mixture of MgCl2+ethanol (1.12/1%; 20min) showed cardiac function (heart rate, stroke volume, cardiac output) comparable to hearts removed from animals killed under hypothermia. However, 3.5% MgCl2 (1:1, sea water: distilled water, 20min) produced a significant impairment of the Frank-Starling response as did 45min exposure to the MgCl2+ethanol mixture. Perfusion of the isolated heart with MgCl2±ethanol formulations produced a concentration-related bradycardia (and arrest), a decreased stroke volume and cardiac output indicating a direct effect on the heart. The cardiac effects of MgCl2 are discussed in relation to the involvement of magnesium, sodium, chloride and calcium ions, exposure time and osmolality of the formulations and the implications for the use of various formulations of MgCl2 as anaesthetics in octopus. Overall, provided that the in vivo exposure to 3.5% MgCl2 in sea water or to a mixture of MgCl2+ethanol is limited to ~20min, residual effects on cardiac function are unlikely to impact post-anaesthetic recovery.
 

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