Vargas-González Alvaro, Prado-Zayago Esteban, León-Olea Martha, Guarner-Lans Verónica, Cano-Martínez Agustina
Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", (INCICH, Juan Badiano No. 1 Col. Sección XVI, Tlalpan 14080, México DF.
Arch Cardiol Mex. 2005 Jul-Sep;75 Suppl 3:S3-21-9.
Ventricular resection of the heart of Ambystoma mexicanum was performed and the type of tissue that restored the lesion and if it is by hypertrophy or hyperplasia of myocardium, were evaluated. Masson's trichrome stain indicated that 5 days after resection, the gap was occupied with a blood clot surrounded by collagen fibres (83 +/- 6%) and muscle (10 +/- 3%) and the rest of area (7 +/- 2%) free of tissue. A proportion of 50 +/- 4 and 90 +/- 2% was muscular tissue, 10 and 30 days after injury. The evaluation with bis-Benzimide indicated cell proliferation in the injured area. The double immunohistochemistry for alpha-sarcomeric actin and proliferating cell nuclear antigen indicated that the tissue that occupied the injury-produced gap was originated by cardiomyocyte proliferation, which presented a maximum of 68%, 5 day after injury. Our results indicate that the myocardium of A. mexicanum recovers its structure through cardiomyocyte hyperplasia and suggest that the myocardial regenerative capacity is higher than the reported for adult mammals (1%) and other non-mammalian vertebrates (32%). This characteristic makes A. mexicanum a suitable model to study the mechanisms that regulate per se, the myocardial regeneration in adult vertebrates in vivo.
对美西螈心脏进行心室切除术，并评估修复损伤的组织类型以及其是通过心肌肥大还是增生来实现的。Masson三色染色显示，切除术后5天，缺口被血凝块占据，血凝块周围是胶原纤维（83±6%）和肌肉（10±3%），其余区域（7±2%）无组织。损伤后10天和30天，肌肉组织的比例分别为50±4%和90±2%。用双苯甲酰亚胺评估显示损伤区域有细胞增殖。α-肌节肌动蛋白和增殖细胞核抗原的双重免疫组化表明，占据损伤产生缺口的组织源自心肌细胞增殖，损伤后5天其比例最高可达68%。我们的结果表明，美西螈的心肌通过心肌细胞增生恢复其结构，并表明其心肌再生能力高于已报道的成年哺乳动物（1%）和其他非哺乳动物脊椎动物（32%）。这一特性使美西螈成为研究体内成年脊椎动物心肌再生自身调节机制的合适模型。
