title: Dietary salt exacerbates isoproterenol-induced cardiomyopathy in rats.
abstract: Spontaneously hypertensive heart failure rats (SHHFs) take longer to develop compensated heart failure (HF) and congestive decompensation than common surgical models of HF. Isoproterenol (ISO) infusion can accelerate cardiomyopathy in young SHHFs, while dietary salt loading in hypertensive rats induces cardiac fibrosis, hypertrophy, and--in a minority-congestive HF. By combining ISO with dietary salt loading in young SHHFs, the authors sought a nonsurgical model that is more time--and resource-efficient than any of these factors alone. The authors hypothesized that salt loading would enhance ISO-accelerated cardiomyopathy, promoting fibrosis, hypertrophy, and biochemical characteristics of HF. SHHFs (lean male, 90d) were infused for 4 wk with ISO (2.5 mg/kg/day) or saline. After 2 wk of infusion, a 6-wk high-salt diet (4%, 6%, or 8% NaCl) was initiated. Eight percent salt increased heart weight, HF markers (plasma B-type natriuretic peptide, IL-6), lung lymphocytes, and indicators of lung injury and edema (albumin and protein) relative to control diet, while increasing urine pro-atrial natriuretic peptide relative to ISO-only. High salt also exacerbated ISO-cardiomyopathy and fibrosis. Thus, combining ISO infusion with dietary salt loading in SHHFs holds promise for a new rat HF model that may help researchers to elucidate HF mechanisms and unearth effective treatments.
authors: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, North Carolina, USA.
authors: Alex P
authors: AP
authors: Carll
authors: Najwa
authors: N
authors: Haykal-Coates
authors: Darrell W
authors: DW
authors: Winsett
authors: Mehdi S
authors: MS
authors: Hazari
authors: Abraham
authors: A
authors: Nyska
authors: Judy H
authors: JH
authors: Richards
authors: Monte S
authors: MS
authors: Willis
authors: Daniel L
authors: DL
authors: Costa
authors: Aimen K
authors: AK
authors: Farraj
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000652:urine; D015415:Biomarkers / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D009202:Cardiomyopathies / Q000139:chemically induced / Q000473:pathology*; D005355:Fibrosis; D006321:Heart / Q000187:drug effects / Q000503:physiopathology*; D006333:Heart Failure / Q000139:chemically induced / Q000473:pathology; D015850:Interleukin-6 / Q000097:blood; D007545:Isoproterenol / Q000633:toxicity*; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood; D051381:Rats; D011918:Rats, Inbred SHR; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D017673:Sodium Chloride, Dietary; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor; D007545:Isoproterenol