Study on Cooling Effect of Intratumoral Blood Flow During Hyperthermia

热疗时瘤内血流冷却作用的研究

• 批准号: 01571083
• 负责人: YAMAZAKI Michio
• 金额: $ 1.34万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01571083/
• 关键词: Hyperthermia; Tumor blood flow; 腫瘍内血流; 昇圧化学療法; 腫瘍血管

(1) DONRYU rats (8 week-old) with transplanted tumor on the back were used in this experiment. The tumors were inserted with thermometry sensors and blood flow sensors and heated by 2450MHz microwave to 43^ﾟC. Blood pressure was simultaneously monitored with catheters in femoral artery. When intratumoral temperature cme to an equilibrium, blood pressure was raised by administration of AngiotensinII. Consequently blood flow in tumor was increased, but intratumoral temperature was almost unchanged.(2) By heating tumors body temperature of rats was raised remarkably. So temperature of blood flowing into tumors was supposed to be high. Therefore we could not verify a hypothesis on cooling mechnism of intratumoral blood flow.(3) At the beginning of the experiment, we thought that heat conduction between blood flow and tumor tissue was important to explain cases in which intratumoral temperature didn't fall in spite of high blood pressure. But we became aware that the cases can be explained if diameters of tumor blood vesels vary as intratumoral temperature changes. High blood pressure produces increase of blood flow in tumor, then cooling of blood vessels of the tumor. If the cooling brings the blood vessels to contraction, tumor blood flow decreases. In short, high blood pressure doesn't increase blood flo w of the tumor, therefore intratumoral temperature doesn't fall.(4) To verify either of above hypotheses, blood must be cooled to 37^ﾟC, immediately before the blood flows in tumor. But the apparatus which can control temperature of blood flow of rats are not easy to make, so we couldn't prepare it in this experiment.

(1)在本实验中使用背部移植有肿瘤的DONRYU大鼠（8周龄）。将肿瘤插入测温传感器和血流传感器，并用2450MHz微波加热至43 ° C。同时用股动脉导管监测血压。当肿瘤内温度达到平衡时，给予血管紧张素II升高血压。因此，肿瘤内的血流量增加，但肿瘤内的温度几乎不变。(2)加热肿瘤使大鼠体温明显升高。所以流入肿瘤的血液温度应该很高。因此，我们无法验证肿瘤内血流冷却机制的假设。(3)在实验开始时，我们认为血流和肿瘤组织之间的热传导对于解释尽管血压高但肿瘤内温度不下降的情况很重要。但是我们意识到，如果肿瘤血管的直径随着肿瘤内温度的变化而变化，则可以解释这些病例。高血压导致肿瘤内血流量增加，然后肿瘤血管冷却。如果冷却使血管收缩，肿瘤血流量就会减少。简而言之，高血压不会增加肿瘤的血流，因此肿瘤内的温度不会下降。(4)为了验证上述任何一种假设，血液必须在血液流入肿瘤之前立即冷却至37 ° C。但由于控制大鼠血流温度的装置不易制作，故本实验未能研制成功。