Biondo-Simões Maria de Lourdes Pessole, Ioshii Sergio Ossamu, Borsato Karin Soldatelli, Zimmermann Elise
Metodologia Científica da PUCPR.
Acta Cir Bras. 2005;20 Suppl 1:211-9.
Hypothyroidism is a common situation among the aged which affects protein synthesis. The objective of the present study was to determine the influence of hypothyroidism on the healing process in aged rats.
96 male Wistar rats were used, 48 of them with a mean age of 110 days and 48 with a mean age of 750 days. Half the young animals and half the old ones were euthyroid and half were hypothyroid. Hypothyroidism was obtained by total thyroidectomy. Thirty days after surgery the animals were submitted to median laparotomy followed by laparorrhaphy on 2 synthesis planes. Six animals from each group were submitted to euthanasia by drawing lots on the 3rd, 7th and 14th postoperative day and submitted to macroscopic, resistance, and histopathological analysis.
The resistance of the skin scars was lower in hypothyroid animals, both the young (p = 0.0145) and old (p = 0.0242) ones, with no significant relation with age being detected. The resistance of the scars on the peritoneum-muscle-aponeurosis plane was lower in old animals on the 24th day (p = 0.0014) and even lower in hypothyroid old animals (p = 0.0000). The histological evolution was similar, but differences in collagen presence were observed. On the 7th day the skin scars had a lower collagen content in young (p = 0.0201) and old (p = 0.0003). hypothyroid animals. On the 14th day the scars of old hypothyroid animals had less collagen than those of normal old animals (p = 0.0092) and those of young hypothyroid animals (p = 0.0283). On the 3rd day, the scars of hypothyroid animals on the peritoneum-muscle-aponeurosis plane presented less collagen than those of both young (p = 0.0089) and old (p = 0.0171) normal controls, but there was no relation with age. This association persisted on the 7th and 17th day, but age dependence was observed at these time points.
Analysis of the results permits us to conclude that healing is impaired in the presence of hypothyroidism and worsens with aging.
甲状腺功能减退是老年人中的常见情况，会影响蛋白质合成。本研究的目的是确定甲状腺功能减退对老年大鼠愈合过程的影响。
使用96只雄性Wistar大鼠，其中48只平均年龄为110天，48只平均年龄为750天。一半的年轻动物和一半的老年动物甲状腺功能正常，另一半甲状腺功能减退。通过全甲状腺切除术导致甲状腺功能减退。手术后30天，对动物进行正中剖腹术，然后在两个合成平面上进行腹壁缝合术。每组6只动物在术后第3、7和14天通过抽签实施安乐死，并进行宏观、抗张强度和组织病理学分析。
甲状腺功能减退的动物，无论年轻（p = 0.0145）还是老年（p = 0.0242），皮肤瘢痕的抗张强度均较低，未检测到与年龄有显著关系。在第24天，老年动物腹膜-肌肉-腱膜平面瘢痕的抗张强度较低（p = 0.0014），而甲状腺功能减退的老年动物更低（p = 0.0000）。组织学演变相似，但观察到胶原存在差异。在第7天，年轻（p = 0.0201）和老年（p = 0.0003）甲状腺功能减退动物的皮肤瘢痕胶原含量较低。在第14天，老年甲状腺功能减退动物的瘢痕胶原比正常老年动物（p = 0.0092）和年轻甲状腺功能减退动物（p = 0.0283）少。在第3天，甲状腺功能减退动物腹膜-肌肉-腱膜平面的瘢痕胶原比年轻（p = 0.0089）和老年（p = 0.0171）正常对照均少，但与年龄无关。这种关联在第7天和第17天持续存在，但在这些时间点观察到年龄依赖性。
对结果的分析使我们得出结论，甲状腺功能减退会损害愈合，且随着年龄增长而恶化。
