Oxygenation and Vascular Perfusion in Spontaneous and Transplanted Tumor Models

Abstract

Since quantitative measurements of tumor vascular function cannot be obtained in human tumors, appropriate animal tumor models must be utilized. The current studies were undertaken to compare transplantable, murine KHT tumors with primary and 1^st generation transplants of spontaneous mammary carcinomas. To evaluate changes in tumor vascular structure and function, immunostaining of total and perfused vascular spacing, and cryospectrophotometric measurement of intravascular HbO₂ saturations were utilized. KHT tumors demonstrated a distinct pattern of decreasing oxygenation with increasing distance from the tumor surface, while spontaneous tumors exhibited striking intertumor heterogeneities and a reduced dependence of oxygenation on distance from tumor surface. Anatomical/perfused vessel distributions and functional response were similar between the primary and transplanted tumor models, as was tissue histological appearance, but were quite different from KHT tumors. These results indicate that spontaneous tumor vascular configuration and function tend to be preserved in 1^st generation trochar transplanted tumors.