I Stefanon1, D V Vassallo, J G Mill. 1. Departamento de Ciências Fisiológicas, Universidade Federal do Espirito Santo, Vitória, Brasil.
Abstract
STUDY OBJECTIVE: The aim of the study was to examine, in a whole heart preparation, the relationship between length changes in cardiac muscle and tension development and length dependent activation. DESIGN: Rat hearts were perfused by the Langendorff technique and isovolumetric pressure changes in the left ventricle, produced by increasing diastolic pressures (0, 5, 10, 15, 20, 25 mm Hg), were studied at different calcium concentrations (0.5, 1.25, 2.5, 3.75 mmol.litre-1). EXPERIMENTAL MATERIALS: 20 whole heart preparations were obtained from albino rats of either sex, weight 180-240 g (females) and 220-330 g (males). MEASUREMENTS AND MAIN RESULTS: In a comparison of ventricular diastolic upsilon systolic pressure curves, normalised with respect to maximum isovolumetric systolic pressure, there was a separation and an upward displacement of the curves with increments in calcium concentration in the perfusate. CONCLUSIONS: The results show, as in isolated preparations, that there is length dependent activation in the whole rat heart.
STUDY OBJECTIVE: The aim of the study was to examine, in a whole heart preparation, the relationship between length changes in cardiac muscle and tension development and length dependent activation. DESIGN:Rat hearts were perfused by the Langendorff technique and isovolumetric pressure changes in the left ventricle, produced by increasing diastolic pressures (0, 5, 10, 15, 20, 25 mm Hg), were studied at different calcium concentrations (0.5, 1.25, 2.5, 3.75 mmol.litre-1). EXPERIMENTAL MATERIALS: 20 whole heart preparations were obtained from albino rats of either sex, weight 180-240 g (females) and 220-330 g (males). MEASUREMENTS AND MAIN RESULTS: In a comparison of ventricular diastolic upsilon systolic pressure curves, normalised with respect to maximum isovolumetric systolic pressure, there was a separation and an upward displacement of the curves with increments in calcium concentration in the perfusate. CONCLUSIONS: The results show, as in isolated preparations, that there is length dependent activation in the whole rat heart.
Authors: C L V Pereira; C F Ximenes; E Merlo; A S Sciortino; J S Monteiro; A Moreira; B B Jacobsen; J B Graceli; K S Ginsburg; R F Ribeiro Junior; D M Bers; I Stefanon Journal: Environ Pollut Date: 2019-01-16 Impact factor: 8.071
Authors: Ivanita Stefanon; María Valero-Muñoz; Aurélia Araújo Fernandes; Rogério Faustino Ribeiro; Cristina Rodríguez; Maria Miana; José Martínez-González; Jessica S Spalenza; Vicente Lahera; Paula F Vassallo; Victoria Cachofeiro Journal: PLoS One Date: 2013-05-31 Impact factor: 3.240