title: Beta-adrenergic receptors on leukocytes of the channel catfish, Ictalurus punctatus.
abstract: Commercial rearing conditions expose teleost fish to numerous acute and chronic stressors that may precipitate dramatic production losses due to infectious diseases. Chemical mediators released in response to acute stress include the catecholamines, epinephrine and norepinephrine. Mammalian lymphocytes and macrophages express beta-adrenergic receptors (AR) that can bind catecholamines, leading to changes in cell function. In this study, radioligand binding assays demonstrated the presence of beta-AR in membranes isolated from head kidney and spleen leukocytes of the channel catfish, Ictalurus punctatus. Competition with subtype selective antagonists CGP-20,712 (beta1) and ICI-118,551 (beta2) suggested that the beta2-adrenergic receptor is the primary receptor subtype present on these membranes. These data along with the HPLC-quantification of catecholamines in plasma of I. punctatus lend further support to the contention that crosstalk between the neuroendocrine and immune systems in lower vertebrates is mediated in part by stress-related biogenic amines like epinephrine and norepinephrine.
authors.affiliation: Grice Marine Laboratory, The University of Charleston, 205 Fort Johnson Road, Charleston, SC 29412, USA.
authors.forename: Suzanne S
authors.initials: SS
authors.lastname: Finkenbine
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Gettys
authors.forename: Karen G
authors.initials: KG
authors.lastname: Burnett
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002395:Catecholamines / Q000032:analysis; D002397:Catfishes; D002851:Chromatography, High Pressure Liquid; D004837:Epinephrine / Q000097:blood; D007962:Leukocytes / Q000378:metabolism*; D009638:Norepinephrine / Q000097:blood; D011869:Radioligand Assay; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
chemical_list: D002395:Catecholamines; D011943:Receptors, Adrenergic, beta; D009638:Norepinephrine; D004837:Epinephrine