The effects of prolonged epinephrine infusion on the physiology of the rainbow trout, Salmo gairdneri. II. Branchial solute fluxes.
Rainbow trout were infused continuously for 24 h with epinephrine in order to elevate circulating levels to those measured during periods of acute extracellular acidosis (about 5 X 10(-8) mol l-1). Concomitant effects on branchial solute fluxes were evaluated. Epinephrine infusion caused complex and differential adjustments of Na+ and Cl- unidirectional fluxes (influx and efflux) resulting in a significant elevation of the arithmetic difference between Na+ and Cl- net fluxes (JnetNa+-JnetCl-). A significant correlation existed between JnetNa+-JnetCl- and net branchial acid excretion (JnetH+), thereby suggesting a role for epinephrine in piscine acid-base regulation. The stimulation of JnetH+ by epinephrine was due primarily to a reduction in the excretion of titratable acid (JTA) accompanied by non-significant changes in ammonia excretion (JAmm). The results are discussed with respect to a role for epinephrine in regulating acid-base disturbances by interacting with branchial ionic exchange mechanisms.
D000138:Acidosis / Q000503:physiopathology; D000818:Animals; D002712:Chlorides / Q000378:metabolism; D004837:Epinephrine / Q000008:administration & dosage / Q000494:pharmacology*; D005880:Gills / Q000187:drug effects / Q000502:physiology*; D007261:Infusions, Intra-Arterial; D007700:Kinetics; D012487:Salmonidae / Q000502:physiology*; D012964:Sodium / Q000378:metabolism; D014337:Trout / Q000502:physiology*
D002712:Chlorides; D012964:Sodium; D004837:Epinephrine