Accelerated hematopoietic recovery with angiotensin-(1–7) after total body radiation

Purpose: Angiotensin (1–7) [A(1–7)] is a component of the renin angiotensin system (RAS) that stimulates hematopoietic recovery after myelosuppression. In a Phase I/IIa clinical trial, thrombocytopenia after chemotherapy was reduced by A(1–7). In this study, the ability of A(1–7) to improve recovery after total body irradiation (TBI) is shown with specific attention to radiation-induced hematopoietic injury.Materials and methods: Mice were exposed to TBI (doses of 2–7 Gray [Gy]) of cesium 137 gamma rays, followed by treatment with A(1–7), typical doses were 100–1000 μg/kg given once or once daily for a specified number of days depending on the study. Animals are injected subcutaneously via the nape of the neck with 0.1 ml drug in saline. The recovery of blood and bone marrow cells was determined. Effects of TBI and A(1–7) on survival and bleeding time was also evaluated.Results: Daily administration of A(1–7) after radiation exposure improved survival (from 60% to 92–97%) and reduced bleeding time at day ...