Martinez A A, Meshorer A, Meyer J L, Hahn G M, Fajardo L F, Prionas S D
Cancer Res. 1983 May;43(5):2072-5.
We have previously presented a histopathological grading scheme for thermal damage in normal porcine adipose and skeletal muscle tissues. Here we have used this scheme to assess the heat sensitivity of these tissues, and evaluate the protective benefit of thermotolerance as induced by a prior thermal exposure. Tissues were exposed to temperatures ranging from 40-50 degrees for 30 min. Half of all sites also received a thermal exposure of 41.0-43.0 degrees 4 hr earlier. Biopsies for histological evaluation were obtained at 18 to 24 hr ("acute") and at 28 to 31 days ("chronic") following treatment. Only mild acute injury was seen in the early samples, following either single or double heat exposures, at all temperature levels. Minimal chronic damage was also seen in the late samples following single exposures of 45 degrees or less. Higher single exposures caused important chronic lesions, the severity of which was dose dependent. Regions that had received the earlier conditioning thermal exposure showed a significant protection against the subsequent thermal exposure. In such regions, mean (chronic) pathology scores were reduced by 76 to 86% over the temperature range 45-48 degrees. The degree of acute damage failed to predict the degree of chronic damage. Overall, induction of thermotolerance provided an advantage of 2 degrees or more in normal tissue protection.
我们之前提出了一种用于评估正常猪脂肪和骨骼肌组织热损伤的组织病理学分级方案。在此，我们使用该方案来评估这些组织的热敏感性，并评估先前热暴露诱导的热耐受的保护作用。将组织暴露于40至50摄氏度的温度下30分钟。所有部位中有一半在4小时前还接受了41.0至43.0摄氏度的热暴露。在治疗后18至24小时（“急性”）和28至31天（“慢性”）获取用于组织学评估的活检样本。在所有温度水平下，无论是单次还是两次热暴露后，早期样本中仅观察到轻度急性损伤。在45摄氏度或更低的单次暴露后的晚期样本中也观察到最小程度的慢性损伤。更高的单次暴露会导致重要的慢性病变，其严重程度呈剂量依赖性。接受过早期适应性热暴露的区域对随后的热暴露显示出显著的保护作用。在这些区域中，在45至48摄氏度的温度范围内，平均（慢性）病理评分降低了76%至86%。急性损伤的程度无法预测慢性损伤的程度。总体而言，热耐受的诱导在正常组织保护方面提供了2摄氏度或更高的优势。
