EFFECTS OF VASOACTIVE AGENTS ON THE REGIONAL BLOOD FLOW AND THE PERMEABILITY IN MALIGNANT BRAIN TUMORS

本研究旨在探讨血管活性药物对恶性脑肿瘤局部脑血流量（rCBF）和脑通透性的影响。以大鼠胶质瘤模型为研究对象，采用氢清除率法研究了颈动脉内注射多种血管活性药物对脑肿瘤rCBF的影响。脑肿瘤血管在结构和生化上与正常脑血管不同，对血管活性药物如组胺、腺苷、ATP、前列腺素和钙拮抗剂的反应发生改变。在我们的实验中，这些药物在不影响全身生命体征和同侧正常脑组织rCBF的情况下，显著提高了脑肿瘤的rCBF。使用这些药物，rCBF的肿瘤选择性百分比增加从30%到100%不等。虽然脑肿瘤血管中rCBF反应改变的机制有待进一步研究，但这些血管活性药物被认为有潜力用于选择性地增加脑恶性胶质瘤的药物递送。

The research project was aimed to study effects of vasoactive agents on the regional cerebral blood flow (rCBF) and the permeability in malignant brain tumors. We studied the effect of the intracarotid administration of various vasoactive agents on the rCBF in brain tumors by hydrogen clearance method using a rat glioma model. The brain tumor vessels are structually and biochemically different from the normal brain vessels, and show an altered response to vasoactive agents, such as histamine, adenosine, ATP, prostacycline (PGI_2), and calcium antagonists. In our experiment, these agents have elevated the rCBF in the brain tumor significantly without affecting the systemic vital signs and the rCBF in the ipsilateral normal brain tissue. The tumor selective percent increase of the rCBF ranged from 30 to 100 % with these agents. Although the mechanism of altered response of the rCBF in the brain tumor vessels should be further investigated, these vasoactive agents are considered to have the potential to be utilized to selectively increase drug deliverry to malignant glioma in the brain.