Control of thermoregulatory evaporation in the waterproof treefrogChiromantis xerampelina

1.	At ambient temperatures (T a) between 39 and 43°C, specimens of the waterproof treefrogChiromantis xerampelina, resting quietly in wind tunnels, adjust rates of evaporative water loss (EWL), maintaining body temperature (T b) 2–4°C belowT a.
2.	Brain heating and cooling, respectively, increased and decreased steady-state rates of thermoregulatory evaporative water loss (EWL), driving negative feedback changes inT b.
3.	Continuous infusions of epinephrine resulted in specific, dose-dependent, saturable increases in EWL; isoproterenol was more potent than epinephrine, which was more potent than phenylephrine. Tyramine injection also stimulated EWL.
4.	Non-specific increases in EWL stimulated by injections of cholinergic agonists were weakly antagonized by atropine, but thermally induced EWL, as well as adrenergically and cholinergically stimulated increases in EWL, were abolished by beta-adrenergic antagonists.
5.	Sweating decreased andT b increased during ganglionic blockade.
6.	The observations suggest thatC. xerampelina controls thermoregulatory EWL by modulating the sympathetic nervous outflow stimulating beta-adrenergic receptors on cutaneous mucous glands.