Evaluation of insulin-like growth factor-1 in a mouse model of long-term abdominal radiation toxicity.

The purpose of these experiments was to test whether a brief course of insulin-like growth factor-1 (IGF-1) injection (escalating doses) concomitant to irradiation ameliorates radiation-induced kidney dysfunction and lethal bowel toxicity in a mouse model of unilateral high-dose irradiation of the kidney and adjacent bowel. The kidney function was assessed by means of repeated 99mTc-dimercaptosuccinate scans (every six weeks) during a maximum follow-up of 49 weeks. The experiments with single fractions of 12 Gy and 15 Gy revealed only minor differences in the severity of kidney dysfunction and no reduction in lethal bowel toxicity from IGF-1 treatment In the absence of any significant radioprotective effect, other strategies of response modification need to be developed.