Gullino P M, Jain R K, Grantham F H
J Natl Cancer Inst. 1982 Mar;68(3):519-33.
Temperature gradients of mammary tumors in randombred Sprague-Dawley rats under normothermia, hypothermia, and hyperthermia were determined, and their experimental modifications were utilized to assess differences in perfusion rates within the neoplastic tissue. Normothermic tumors showed a circadian rhythm with zenith at midnight and nadir at midday. Differences between highest and lowest temperatures recorded during the 24-hour period reached up to 3 degrees C. Similar oscillations were observed in subcutaneous tissue without tumor. An average temperature increment of 0.5-1.0 degrees C was observed when a tumor was transferred from the subcutaneous to the abdominal location. Gradients larger than 1 degrees C were observed within the same tumor in locations only a few millimeters distance from each other. The nonuniformity in temperature within normothermic tumors was exaggerated during hyperthermia. No appreciable change in temperature gradients was seen within a normothermic tumor when tumor blood flow was doubled or reduced to one-third of the basal level. Hyperthermia increased both volume and temperature of tumor efferent blood. As expected, decrease or increase in blood flow during hyperthermia increased or decreased tumor temperature, respectively, but substantial temperature gradients up to 2 degrees C still persisted within adjacent regions. The extent of temperature changes in the tumor could not be correlated with a known change in blood supply. A pulse of cold serum into the tumor afferent artery produced a substantial reduction of tumor blood flow, but only a small depression in tumor temperatures, and a very small change in tumor temperature gradients. No appreciable modification could be brought about in tumor temperature levels and temperature gradients within the tumor by pulses of cold serum in the afferent artery during hyperthermia. After external cooling of the tumor, the time necessary to compensate for temperature depression did not correlate with either the reduction of temperature or with the thickness of the tumor tissue separating the thermistor from the cold source. The results indicate extensive anisotropy of temperature and blood distribution within growing neoplastic tissue and suggest that heat transfer by convection within the tumor is much less effective than it is commonly assumed.
测定了正常体温、低温和高温条件下随机繁殖的斯普拉格-道利大鼠乳腺肿瘤的温度梯度，并利用对其进行的实验性改变来评估肿瘤组织内灌注率的差异。正常体温的肿瘤呈现昼夜节律，午夜时达到峰值，中午时降至最低点。24小时内记录的最高温度与最低温度之间的差异可达3摄氏度。在无肿瘤的皮下组织中也观察到了类似的波动。当肿瘤从皮下转移到腹部位置时，观察到平均温度升高了0.5-1.0摄氏度。在同一肿瘤内，彼此距离仅几毫米的位置之间观察到大于1摄氏度的梯度。在高温期间，正常体温肿瘤内温度的不均匀性被放大。当肿瘤血流量增加一倍或减少至基础水平的三分之一时，正常体温肿瘤内的温度梯度未见明显变化。高温增加了肿瘤流出血液的体积和温度。正如预期的那样，高温期间血流量的减少或增加分别降低或升高了肿瘤温度，但相邻区域内仍存在高达2摄氏度的显著温度梯度。肿瘤内温度变化的程度与已知的血液供应变化无关。向肿瘤传入动脉注入一剂冷血清会使肿瘤血流量大幅减少，但仅使肿瘤温度略有降低，且肿瘤温度梯度变化很小。在高温期间，通过向传入动脉注入冷血清，无法使肿瘤内的温度水平和温度梯度发生明显改变。对肿瘤进行外部冷却后，补偿温度降低所需的时间与温度降低幅度或热敏电阻与冷源之间肿瘤组织的厚度均无关联。结果表明，在生长的肿瘤组织内，温度和血液分布存在广泛的各向异性，提示肿瘤内通过对流进行的热传递远比通常认为的效率低。
