Recovery of the baroreflex and autonomic modulation after anesthesia with MS-222 in bullfrogs.

The time course for recovery after anesthesia is poorly described for tricaine methanesulfonate (MS-222). We suggest that the baroreflex and the heart rate variability (HRV) could be used to index the recovery of the autonomic modulation after anesthesia. We analyzed the recovery profile of behavioral and physiological parameters over time to analyze the progression of recovery after anesthesia of American bullfrogs with MS-222.

Baroreflex responses to activity at different temperatures in the South American rattlesnake, Crotalus durissus.

In humans, physical exercise imposes narrower limits for the heart rate (f) response of the baroreflex, and vascular modulation becomes largely responsible for arterial pressure regulation. In undisturbed reptiles, the baroreflex-related f alterations at the operating point (G) decreases at elevated body temperatures (T) and the vascular regulation changes accordingly. We investigated how the baroreflex of rattlesnakes, Crotalus durissus, is regulated during an activity at different T, expecting that activity would reduce the capacity of the cardiac baroreflex neural pathway to buffer arterial pressure fluctuations while being compensated by the vascular neural pathway regulation.