Disparate responses of tumour vessels to angiotensin II: tumour volume-dependent effects on perfusion and oxygenation

• DOI: 10.1054/bjoc.2000.1229
• Publication Date: 2002-07-26T11:32:43Z
• Authors: O Thews; D K Kelleher; P Vaupel
• Keywords: Male; 0301 basic medicine; Angiotensin II; Regular Article; Neoplasms, Experimental; Rats; 3. Good health; Oxygen; Perfusion; Rats, Sprague-Dawley; Disease Models, Animal; 03 medical and health sciences; 0302 clinical medicine; Regional Blood Flow; Laser-Doppler Flowmetry; Animals; Vasoconstrictor Agents

Perfusion and oxygenation of experimental tumours were studied during angiotensin II (AT II) administration whereby the rate continuous AT infusion was chosen to increase mean arterial blood pressure (MABP) by 50–70 mmHg. In subcutaneous DS- sarcomas red cell (RBC) flux assessed using laser Doppler technique tumour oxygen partial (pO2) measured polarographically O2-sensitive catheter needle electrodes. Changes in RBC with increasing MABP depended mainly on size. small tumours, decreased rising whereas larger increased parallel MABP. As a result these volume-dependent effects flow, impact pO2 also volume-related. infusion, large positive relationship between O2 status found. This disparate behaviour might be co-existence two functionally distinct populations vessels. perfusion decreases presumably due vasoconstriction pre-existing host vessels feeding tumour. malignancies, newly formed predominate seem not have this vasoresponsive capability (lack smooth muscle cells and/or receptors), resulting an improvement which is tumour-related per se, but pressure. © 2000 Cancer Research Campaign