title: Canine dilated cardiomyopathy: lymphocyte and cardiac alpha(1)- and beta-adrenoceptor concentrations in normal and affected great danes.
abstract: Serum catecholamine levels and myocardial and lymphocyte adrenergic receptor (AR) concentrations were measured in adult great danes affected by canine dilated cardiomyopathy (DCM) and compared to those of healthy animals. A non-homogeneous population of beta -AR, consisting of beta(1)-AR and beta(2)-AR, was observed in healthy (41 and 59%, respectively) and affected (17 and 83%, respectively) dog lymphocytes. Binding assays revealed that total beta -AR, beta(1)-AR and alpha(1)-AR were significantly downregulated (P<0.05;P<0.01;P<0. 001), both in lymphocyte and myocardial cell membranes of affected dogs. beta(2)-Adrenergic receptor concentrations were significantly reduced only in lymphocyte and right atrium cell membranes (P<0.05). Downregulation was not associated with alterations in receptor binding characteristics, as no significant differences in K(d)values were found. Mean plasma catecholamine levels were significantly higher (P<0.01) in DCM dogs (939+/-41) than in normal subjects (348+/-32), thus suggesting a sympathetic activation. The present study indicates a condition similar to that observed in human patients affected by DCM and that adrenergic receptors in canine lymphocytes reflect the fluctuation of adrenergic receptor concentrations in the myocardium.
authors.affiliation: Department of Animal Pathology, Division of Veterinary Pharmacology & Toxicology, via Nizza 52, Torino, I-10126, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Re
authors.forename: L
authors.initials: L
authors.lastname: Bergamasco
authors.forename: P
authors.initials: P
authors.lastname: Badino
authors.forename: M
authors.initials: M
authors.lastname: Borgarelli
authors.forename: R
authors.initials: R
authors.lastname: Odore
authors.forename: A
authors.initials: A
authors.lastname: Tarducci
authors.forename: R
authors.initials: R
authors.lastname: Zanatta
authors.forename: C
authors.initials: C
authors.lastname: Girardi
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000737:chemistry; D000319:Adrenergic beta-Antagonists / Q000737:chemistry; D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000503:physiopathology / Q000662:veterinary*; D002395:Catecholamines / Q000097:blood; D004283:Dog Diseases / Q000097:blood / Q000503:physiopathology*; D004285:Dogs; D004562:Electrocardiography / Q000662:veterinary; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000503:physiopathology / Q000662:veterinary*; D018655:Lymphocyte Count / Q000662:veterinary; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D011224:Prazosin / Q000737:chemistry; D011412:Propanolamines / Q000737:chemistry; D011941:Receptors, Adrenergic / Q000032:analysis* / Q000097:blood; D018340:Receptors, Adrenergic, alpha-1 / Q000032:analysis / Q000097:blood / Q000737:chemistry; D018342:Receptors, Adrenergic, beta-1 / Q000032:analysis / Q000097:blood / Q000737:chemistry; D018343:Receptors, Adrenergic, beta-2 / Q000032:analysis / Q000097:blood / Q000737:chemistry
chemical_list: D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D002395:Catecholamines; D011412:Propanolamines; D011941:Receptors, Adrenergic; D018340:Receptors, Adrenergic, alpha-1; D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2; C026777:ICI 118551; C033394:CGP 12177; D011224:Prazosin