ABSTRACT
OBJECTIVE: To examine the cytoprotective effect of melatonin or recombinant human growth hormone (hGH) on the early phase of a running myocardial infarction in rats by using the Feulgen staining. METHODS: Rats were subjected to surgical ligature of the left coronary artery or its sham-operation and were studied 1.5 3 h later. Melatonin was administered in the drinking water (100 microg/ml water) for 7 days before surgery. Recombinant hGH (2 IU/kg) was given ip at the time of surgery. Feulgen-stained histological cardiac sections were examined by light microscopy and image analysis. RESULTS: Infarcted rats receiving vehicle exhibited large, diffuse cardiac lesions with a marked positivity for Feulgen reaction. About 18 20% of the total area recorded became injured 1.5 or 3 h after infarction, respectively. Infarcted rats treated with melatonin or hGH, or the combination of both, and killed 3 h after surgery, showed cardiac sections with scattered lesions and only a few isolated injured muscle fibers. A similar effectiveness of melatonin and hGH, alone or in combination, to decrease injured area by 86 87% and the number of cardiac lesions by 75 80% was observed. CONCLUSION: A significant cytoprotective effect of melatonin or hGH is demonstrable in an early phase of myocardial infarction in rats.
Subject(s)
Cytoprotection/drug effects , Growth Hormone/therapeutic use , Heart/drug effects , Melatonin/therapeutic use , Myocardial Infarction/prevention & control , Rosaniline Dyes , Animals , Coloring Agents , DNA/analysis , Disease Models, Animal , Drug Evaluation, Preclinical , Drug Therapy, Combination , Male , Myocardial Infarction/pathology , Myocardium/pathology , Rats , Rats, Wistar , Treatment OutcomeABSTRACT
La histología comparativa de los aneurismas ventriculares de la Cardiopatía Isquémica y la Cardiopatía Chagásica Crónica reviste importancia no sólo desde el punto de vista del diagnóstico diferencial entre ambas, sino también por la presencia de algunos elementos vinculados seguramente con un sector común de la fisiopatología de los aneurismas de ventrículo. Una diferente puesta en marcha de los mecanismos de cicatrización conectiva jugaría, a nuestro parecer, un papel de importancia en la diferente incidencia de aneurisma de ventrículo que ostentan ambas entidades. A pesar de las diferencias etiológicas entre la Cardiopatía Isquémica y la Cardiopatía Chagásica Crónica, la fisiopatología temprana tiene valor comparativo en ambas entidades y algunos de los hallazgos histológicos corroborarían esta hipótesis. Presentamos el estudio histológico de 8 enfermos con aneurismas ventriculares del ventrículares izquierdo, 5 de origen chagásico y 3 de origen isquémico
