title: Tonin in rat heart with experimental hypertrophy.
abstract: The present study was undertaken to determine tonin expression and activity in rat heart presenting isoproterenol-induced hypertrophy. Renin, angiotensin-converting enzyme (ACE), and angiotensinogen (AG) expression were also determined. Wistar rats were treated with isoproterenol for 7 days (5 mg x kg(-1) x day(-1) sc). For untreated animals, the levels of tonin-specific activity in the atrium were 2.6- and 5.5-fold higher than those of the left and right ventricle, respectively. After treatment, the levels of tonin-specific activity increased twofold in the atrium but did not change in the ventricles. Renin expression was not detectable in these structures, and ACE expression levels did not change with treatment. AG expression was detected in the left ventricle at very low levels compared with the atrium and increased significantly only in the hypertrophied atrium (1.8-fold). Tonin mRNA was not detected in the ventricle but was found at low levels in the atrium, which increased after isoproterenol treatment. Our results permit us to conclude that tonin may play a role in the process of heart hypertrophy in the rat.
authors.affiliation: Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Brazil. jlpesq@icb.ufmg.br
authors.forename: Julio Cesar
authors.initials: JC
authors.lastname: Borges
authors.forename: José Antônio
authors.initials: JA
authors.lastname: Silva
authors.forename: Maria Aparecida
authors.initials: MA
authors.lastname: Gomes
authors.forename: Eliane Sa Lopes
authors.initials: ES
authors.lastname: Lomez
authors.forename: Katia Moraes
authors.initials: KM
authors.lastname: Leite
authors.forename: Ronaldo Carvalho
authors.initials: RC
authors.lastname: Araujo
authors.forename: Michael
authors.initials: M
authors.lastname: Bader
authors.forename: João Bosco
authors.initials: JB
authors.lastname: Pesquero
authors.forename: Jorge Luiz
authors.initials: JL
authors.lastname: Pesquero
mesh_terms: D000318:Adrenergic beta-Agonists; D000804:Angiotensin II / Q000096:biosynthesis; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000096:biosynthesis; D006332:Cardiomegaly / Q000139:chemically induced / Q000378:metabolism*; D018450:Disease Progression; D005786:Gene Expression Regulation; D007545:Isoproterenol; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D009929:Organ Size / Q000187:drug effects; D015347:RNA Probes; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020840:Tissue Kallikreins / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D000318:Adrenergic beta-Agonists; D015347:RNA Probes; D000804:Angiotensin II; D009320:Atrial Natriuretic Factor; C117017:tonin; D020840:Tissue Kallikreins; D007545:Isoproterenol