Isoproterenol-induced hypertrophy may result in distinct left ventricular changes

Isoproterenol-induced hypertrophy may result in distinct left ventricular changes

Autor Murad, N. Google Scholar
Tucci, PJF Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Resumo 1. the aim of the present study was to analyse the possible lack of uniformity in isoproterenol (ISO)-induced myocardial hypertrophy.2. Data obtained for isovolumic hearts isolated from 20 rats treated with ISO (0.3 mg/kg over 8 days) were divided into two groups (H-1, n=10; H-2, n = 10) according to the volume (mean +/- SD) needed to change left ventricle diastolic pressure front 0 to 40 mmHg (H-1, 181 +/- 30 mu L; H-2, 108 +/- 14 mu L). Eight control rats (C; 165 +/- 37 mu L) were used for comparison.3. in addition to ventricular distensibility differences, the groups differed in terms of myocardial mass (mean +/- SEM: HI, 181 +/- 3 mg > H-2, 166 +/- 3 mg > C, 136 +/- 3 mg; P < 0.001), of relaxation constant (H-2, 43 +/- 4 msec > H-1, 28 +/- 2 msec; P = 0.0012) and of maximum developed circumferential stress (C, 145 +/- 9 kdyn/cm(2) = H-1, 137 +/- 6 kdynlcm' > H-2, 110 +/- 4 kdyn/cm(2); P = 0.002).4. Our results show that ISO-induced myocardial hypertrophy is not homogeneous. Data obtained for H-2, taken as a whole and compared with H-1 (smaller myocardial mass and impairment of relaxation, elastic stiffness and force generation), suggest that, in some animals, myocardial necrosis and reparative fibrosis may prevail over the stimulus for myocyte growth. the lack of uniformity of ISO-induced myocardial hypertrophy has not been previously reported and may have contributed to the divergence observed in the literature regarding the functional characteristics of the present model.
Assunto cardiac hypertrophy
contractile function
left ventricular distensibility
myocardial mass
Idioma Inglês
Data 2000-05-01
Publicado em Clinical and Experimental Pharmacology and Physiology. Carlton: Blackwell Science Asia, v. 27, n. 5-6, p. 352-357, 2000.
ISSN 0305-1870 (Sherpa/Romeo, fator de impacto)
Editor Blackwell Science Asia
Extensão 352-357
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000087319500005

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