Resistance to Anesthesia by Tricaine Methanesulfonate (TMS, MS-222) in the Chubby Frog (Kaloula pulchra; Microhylidae)
Poster Number
21
Format
Poster Presentation
Faculty Mentor Name
Marcos Gridi-Papp
Faculty Mentor Department
Biological Sciences
Abstract/Artist Statement
Tricaine methanesulfonate (TMS) is a fish and amphibian anesthetic that became popular because of its ease of use and rapid recovery times. The anesthetic is normally administered in a water bath where the concentration of the solution and exposure time determine the depth of anesthesia. We measured the anesthetic response of chubby frogs (Kaloula pulchra; Microhylidae) by testing their sensitivity to a range of anesthetic concentrations from those used to anesthetize other amphibians (0.1-0.2 g/l), through levels used to euthanize amphibians (1 g/l), to the saturation point for the solution at a neutralized pH (8 g/l). To determine the level of sedation, we monitored the heart rate, buccal pumping, and the limb retraction response to tactile stimulation of the animals. In order to rule out skin impermeability to TMS as a factor of resistance, we administered TMS intraperitoneally. Finally, to verify if the resistance of chubby frogs to anesthesia is specific to TMS, we administered ketaminediazepam. We found that the chubby frogs resisted TMS up to the highest concentrations tested as a bath or intraperitoneally. When anesthetized by ketamine-diazepam, however, they were sedated at the same doses employed in other species. These results indicate that chubby frogs don't resist TMS through skin impermeability, but through fast metabolism, renal elimination or immunity to the drug. The resistance of chubby frogs to TMS is far afield from any previously observed in amphibians and points to the greatly unexplored variability of this group in its response to anesthesia.
Location
DeRosa University Center, Ballroom
Start Date
26-4-2014 2:00 PM
End Date
26-4-2014 4:00 PM
Resistance to Anesthesia by Tricaine Methanesulfonate (TMS, MS-222) in the Chubby Frog (Kaloula pulchra; Microhylidae)
DeRosa University Center, Ballroom
Tricaine methanesulfonate (TMS) is a fish and amphibian anesthetic that became popular because of its ease of use and rapid recovery times. The anesthetic is normally administered in a water bath where the concentration of the solution and exposure time determine the depth of anesthesia. We measured the anesthetic response of chubby frogs (Kaloula pulchra; Microhylidae) by testing their sensitivity to a range of anesthetic concentrations from those used to anesthetize other amphibians (0.1-0.2 g/l), through levels used to euthanize amphibians (1 g/l), to the saturation point for the solution at a neutralized pH (8 g/l). To determine the level of sedation, we monitored the heart rate, buccal pumping, and the limb retraction response to tactile stimulation of the animals. In order to rule out skin impermeability to TMS as a factor of resistance, we administered TMS intraperitoneally. Finally, to verify if the resistance of chubby frogs to anesthesia is specific to TMS, we administered ketaminediazepam. We found that the chubby frogs resisted TMS up to the highest concentrations tested as a bath or intraperitoneally. When anesthetized by ketamine-diazepam, however, they were sedated at the same doses employed in other species. These results indicate that chubby frogs don't resist TMS through skin impermeability, but through fast metabolism, renal elimination or immunity to the drug. The resistance of chubby frogs to TMS is far afield from any previously observed in amphibians and points to the greatly unexplored variability of this group in its response to anesthesia.