Direct effects of acute administration of 3, 5, 3′ triiodo-l-thyronine on myocyte function

摘要: Abstract Recent studies have suggested that acute administration of 3, 5, 3′ triiodo-l-thyroninc (T 3 ) may increase ventricular performance; however, the direct cellular effects T are not understood. The objectives this study were to determine (1) whether acts directly on cardiac muscle cell (myocyte) itself, and (2) independently myocyte β-adrenergic receptor. Accordingly, isolated function was examined using video-microscopy in normal porcine myocytes (n = 60) control state presence increasing concentrations (10 500 pmol/L). caused shortening extent, velocity, lengthening velocity a dose-dependent manner. For example, increased from 49.2 ± 4.3 μm/s at baseline 66.5 6.1 with 100 pmol/L ( p further 168.5 10.9 μm/s. Analysis variance revealed independent additive receptor system. In summary, contractile performance, these stimulation. Thus, provide novel modality improve left