title: Salt sensitivity in experimental thyroid disorders in rats.
abstract: This study assessed salt sensitivity, analyzing the effects of an increased saline intake on hemodynamic, morphological, and oxidative stress and renal variables in experimental thyroid disorders. Six groups of male Wistar rats were used: control, hypothyroid, hyperthyroid, and the same groups treated with salt (8% via food intake). Body weight, blood pressure (BP), and heart rate (HR) were recorded weekly for 6 wk. Finally, BP and HR were recorded directly, and morphological, metabolic, plasma, and renal variables were measured. High-salt intake increased BP in thyroxine-treated rats but not in control or hypothyroid rats. High-salt intake increased cardiac mass in all groups, with a greater increase in hyperthyroid rats. Urinary isoprostanes and H(2)O(2) were higher in hyperthyroid rats and were augmented by high-salt intake in all groups, especially in hyperthyroid rats. High-salt intake reduced plasma thyroid hormone levels in hyperthyroid rats. Proteinuria was increased in hyperthyroid rats and aggravated by high-salt intake. Urinary levels of aminopeptidases (glutamyl-, alanyl-, aspartyl-, and cystinylaminopeptidase) were increased in hyperthyroid rats. All aminopeptidases were increased by salt intake in hyperthyroid rats but not in hypothyroid rats. In summary, hyperthyroid rats have enhanced salt sensitivity, and high-salt intake produces increased BP, cardiac hypertrophy, oxidative stress, and signs of renal injury. In contrast, hypothyroid rats are resistant to salt-induced BP elevation and renal injury signs. Urinary aminopeptidases are suitable biomarkers of renal injury.
authors.affiliation: Departamento de Fisiología, Facultad de Medicina, Granada, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Perez-Abud
authors.forename: Isabel
authors.initials: I
authors.lastname: Rodríguez-Gómez
authors.forename: Ana Belén
authors.initials: AB
authors.lastname: Villarejo
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Moreno
authors.forename: Rosemary
authors.initials: R
authors.lastname: Wangensteen
authors.forename: Mohamed
authors.initials: M
authors.lastname: Tassi
authors.forename: Francisco
authors.initials: F
authors.lastname: O'Valle
authors.forename: Antonio
authors.initials: A
authors.lastname: Osuna
authors.forename: Félix
authors.initials: F
authors.lastname: Vargas
mesh_terms: D000626:Aminopeptidases / Q000652:urine; D000818:Animals; D015415:Biomarkers / Q000652:urine; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D006332:Cardiomegaly / Q000378:metabolism / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006977:Hypertension, Renal / Q000378:metabolism / Q000503:physiopathology; D006980:Hyperthyroidism / Q000378:metabolism / Q000503:physiopathology*; D007037:Hypothyroidism / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D018384:Oxidative Stress / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D017673:Sodium Chloride, Dietary / Q000494:pharmacology*; D013963:Thyroid Hormones / Q000097:blood
chemical_list: D015415:Biomarkers; D017673:Sodium Chloride, Dietary; D013963:Thyroid Hormones; D000626:Aminopeptidases