[Tumor vascularity under hypertension induced by intravenous infusion of angiotensin II--angiographic and radionuclide angiographic observations].
Elevation of the mean arterial blood pressure to approximately 150 mmHg by infusion of AT II resulted in selective increase of blood flow in animal tumors without increasing the blood flow in normal tissue. We studied whether or not the blood flow of tumors was increased by AT-II-induced hypertension in patients. Angiograms of 51 patients before and after intravenous infusion of AT-II were compared carefully from 5 points of view which suggested increased tumor blood flow. These were, Contraction of small arteries feeding normal tissue, Enhanced visualization of tumor vessels, Enhanced visualization of tumor stain, Increase of venous return from tumor-bearing region, and Enhanced visualization of metastatic lymph nodes. The results were as follows. Contractions of small arteries feeding normal tissue [Finding 1)] were observed in 34 cases (66.6%) and enhanced visualization of tumor vessels, tumor stain and so on [Finding 2)-5] were observed in 18 cases (35.3%). Consequently, an increase of tumor blood flow was suggested in 40 cases (78.4%). Blood flow of human tumors and normal tissue during the full course of induced hypertension with AT-II were measures by means of radionuclide angiography (99mTc-RBC) and laser Doppler velocimetry. Activities of the tumor-bearing region and the mid-portion of the thigh (selected as normal tissue) were measured continuously by collimated scintillation detectors. In 26 measurements out of 31 (83.8%), the activity in the thigh decreased promptly and returned to the baseline synchronously with the rise and fall of blood pressure. In contrast, in 11 measurements (34.4%) the activity of the tumor-bearing region increased and returned to the baseline accompanying the change of blood pressure. Preliminary observations using laser Doppler velocimetry revealed an increase of blood flow in 5 tumors. In conclusion, the blood flow of human tumors was increased by AT-II, in agreement with the findings in animal tumors.
D000792:Angiography; D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology*; D001158:Arteries / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects*; D006801:Humans; D007263:Infusions, Parenteral; D007834:Lasers; D008207:Lymphatic Metastasis; D009369:Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D012212:Rheology; D014661:Vasoconstriction; D014680:Veins / Q000503:physiopathology
D000804:Angiotensin II