Pulmonary Vascular Injury in a Rat Model of Single Fraction Total Body Irradiation
Radiation Research Society
Annual Meeting of the Radiation Research Society
Under the objectives of the Centers for Medical Countermeasures Against Radiation we have developed animal models of radiation injury. The threat of nuclear or radiological terrorism as well as the broadening role of radiation therapy in oncology establishes imperatives to quantify exposure and mitigate effects before injury becomes evident. Our group concentrates its efforts on understanding and treating radiation-induced lung vascular injury. In this study we investigated a rat model of 10 Gy single fraction penetrating radiation injury combined with bone marrow transplant (BMT) and measured indices of health and lung function at 2 and 8 months (m) after injury. The following is a summary of results in irradiated rats compared to age-matched controls. Body weight and hematocrit levels are significantly decreased at 8-m. Normalized dry lung weight is significantly increase at 2-m and remains so at 8-m. Angiotensin converting enzyme (ACE) activity is significantly decreased at 2-m, but tends to increase at 8-m. Right ventricular hypertrophy and pulmonary vascular resistance are significantly increased at 2-m, but significantly decreased at 8-m. Indices measured in rats not exposed to radiation but given BMT are similar to 0 Gy controls, however there is a significant increase in pulmonary vascular resistance measured at 2-m and a tendency for increased lung ACE activity at both 2 and 8 month time points.