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）和通透性的影响。采用氢清除法研究了不同血管活性药物对大鼠脑胶质瘤rCBF的影响。脑肿瘤血管在结构和生化上与正常脑血管不同，并且对血管活性剂如组胺、腺苷、ATP、前列环素（PGI_2）和钙拮抗剂的反应发生改变。在我们的实验中，这些药物在脑肿瘤中显著升高rCBF，而不影响全身生命体征和同侧正常脑组织中的rCBF。这些药物的肿瘤选择性rCBF增加百分比范围为30%至100%。虽然脑肿瘤血管中rCBF反应改变的机制还有待进一步研究，但这些血管活性药物被认为具有选择性增加脑恶性胶质瘤药物递送的潜力。

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.