beta-Adrenergic regulation of Na~+ uptake by larval zebrafish Danio rerio in acidic and ion-poor environments

摘要

The potential role of adrenergic systems in regulating Na+ uptake in zebrafish {Danio rerio) larvae was investigated. Treatment with iso-proterenol (a generic beta-adrenergic receptor agonist) stimulated Na+ uptake, whereas treatment with phenylephrine (an a i -adrenergic receptor agonist) as well as clonidine (an a2-adrenergic receptor agonist) significantly reduced Na+ uptake, suggesting opposing roles of a- and beta-adrenergic receptors in Na+ uptake regulation. The increase in Na+ uptake associated with exposure to acidic water (pH = 4.0) was attenuated in the presence of the nonselective beta-receptor antagonist propranolol or the Pi-receptor blocker atenolol; the beta_2-receptor antagonist ICI-118551 was without effect.