Blood flow, volume and arterio-venous passages in induced mammary tumours of the rat

• Objective To study blood flow, vascular volume and arterio-venous passages in induced mammary tumours of the rat to characterize parameters possibly responsible for tumour hyponutrition. Method Dimethylbenzanthracene-induced mammary tumours in Sprague-Dawley rats were studied. Regional blood flow was studied by use of the radioactive microsphere tracer technique using 141Cerium-labelled 15 μm spheres coinjected into the left cardiac ventricle with 125Iodine-labelled 25 μm spheres. Blood volume was studied by use of 125Iodine- or 99mTechnetium-labelled human serum albumin, the latter allowing autoradiography of tumour sections for visualization of flow and volume. Results Twenty-seven rats with 170 tumours had a mean tumour blood flow of 48 and 67 mL × min− 1 × 100 g− 1 using 15 and 25 μm sphere data, respectively, indicating a significant passage through vessels between 15 and 25 μm. The lungs showed a “nominal bronchial” blood flow of 260 and 135 mL × min− 1 × 100 g− 1 for the 15 and 25 μm spheres, respectively, indicating pulmonary trapping, particularly of small spheres passing the systemic circulation in vessels larger than 15 μm. There was a positive correlation between the total tumour blood flow within individual rats and trapped spheres of both dimensions in the lungs, indicating shunts also larger than 25 μm. Normal tissues disclosed only small differences in regional blood flow as measured by the two spheres. Blood volume was studied in 20 rats with 120 tumours, with a vascular volume of 3.6 mL × 100 g− 1 representing a blood turnover > 15 times/min. Blood volume co-localized with perfusion as seen in autoradiographs. Conclusion In induced rat mammary tumours, a high fraction of blood, 28%, passes arterio-venous vessels between 15 and 25 μm and there also exist passages > 25 μm. These findings indicate that the functional capacity of the tumour vascular bed might be impaired, adding to the abnormal microenvironment of tumours. © 2017 Elsevier Inc.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Blood flow

Rat

Tumourvascular shunts

albumin

iodine 125

microsphere

microsphere ce 141

technetium 99m

albumin blood level

animal experiment

animal tissue

arteriovenous shunt

Article

blood flow velocity

blood flowmetry

blood pressure measurement

blood volume

body weight

breast tumor

controlled study

female

heart rate

heart weight

lung circulation

nonhuman

priority journal

radioactivity

systolic blood pressure

tumor blood flow

tumor growth

tumor microenvironment

tumor volume

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)