The Role of β-Adrenoreceptors in the Recovery from Exhaustive Exercise of Freshwater-Adapted Rainbow Trout

摘要: Rainbow trout, fitted with arterial catheters, were exercised to exhaustion by manual chasing and then injected either saline (controls), the β-agonist isoproterenol or β-antagonist propranolol. Blood acid-base status, branchial unidirectional net fluxes of Na + Cl − , ammonia acidic equivalents ( J H ) monitored over subsequent 4 h recovery. These same parameters also in normoxic, resting fish following injection acute post-exercise elevation external NaCl concentration. In addition confirming an important role for β-adrenoreceptors regulation gas exchange red cell oxygenation we find a significant β-adrenergic involvement flux lactic acid from muscle across gills. Both infusion (into nonexercised fish) exhaustive exercise found cause excretion. The was further augmented elevating [NaCl] but not affected, this instance, β-stimulation blockade, indicating that entirely regulated mechanism. On basis detailed analysis fluxes, conclude increase arose mainly increased /H (NH upper limit on set supply counterions ionic permeability invariably accompanies exercise.