title: Differential expression of TNF-alpha, IL-6, and IGF-1 by graded mechanical stress in normal rat myocardium.
abstract: An isovolumic normal rat heart Langendorff model was used to examine the effects of moderate (15 mmHg) and severe (35 mmHg) mechanical stretch on the time course (from 0 to 60 min) of myocardial expression of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and insulin-like growth factor (IGF)-1 and their cognate receptors. After 10 min of moderate stretch, TNF-alpha was de novo expressed, whereas constitutive IL-6 and IGF-1 levels were slightly upregulated; no further changes occurred up to 60 min. In comparison, severe stretch resulted in a higher and progressive increase in TNF-alpha, IL-6, and IGF-1 expression up to 20 min. After 20 min, whereas TNF-alpha expression further increased, IL-6 and IGF-1 levels progressively reduced to values lower than those observed under moderate stretch and in unstretched (5 mmHg) control myocardium (IL-6). Mechanical stretch did not significantly alter the expression of the cognate receptors. Indeed, the TNF-alpha receptor (p55) tended to be progressively upregulated under severe stretch over time. The current data provide the first demonstration that TNF-alpha, IL-6, and IGF-1 ligand-receptor systems are differentially expressed within the normal rat myocardium in response to graded mechanical stretch. Such findings may have potential implications with regard to compensatory hypertrophy and failure.
authors.affiliation: Department of Medicina Clinica, Scienze Cardiovascolari ed Immunologiche, L Califano Facoltà di Medcina e Chirurgia, Università degli Studi di Napoli Federico II, Naples, Italy.
authors.forename: Emiliano A
authors.initials: EA
authors.lastname: Palmieri
authors.forename: Giulio
authors.initials: G
authors.lastname: Benincasa
authors.forename: Francesca
authors.initials: F
authors.lastname: Di Rella
authors.forename: Cosma
authors.initials: C
authors.lastname: Casaburi
authors.forename: Maria G
authors.initials: MG
authors.lastname: Monti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: De Simone
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Chiariotti
authors.forename: Lucio
authors.initials: L
authors.lastname: Palombini
authors.forename: Carmelo B
authors.initials: CB
authors.lastname: Bruni
authors.forename: Luigi
authors.initials: L
authors.lastname: Saccà
authors.forename: Antonio
authors.initials: A
authors.lastname: Cittadini
mesh_terms: D000818:Animals; D017931:DNA Primers; D006321:Heart / Q000502:physiology*; D066298:In Vitro Techniques; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D015850:Interleukin-6 / Q000235:genetics*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D017526:Receptor, IGF Type 1 / Q000235:genetics; D019947:Receptors, Interleukin-6 / Q000235:genetics; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D017931:DNA Primers; D015850:Interleukin-6; D019947:Receptors, Interleukin-6; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1