Thalidomide is not able to inhibit radiation-induced heart disease

Abstract

Purpose: Radiotherapy to the thorax increases the risk of radiation-induced heart disease. We and others have shown that local irradiation to the murine heart results in inflammatory and fibrotic responses and decreased microvascular density. In the present study we tested whether thalidomide is able to inhibit radiation-induced heart disease.

Methods: Single doses of 16 Gy or 0 Gy (sham treatment) were delivered to the hearts of mice. At 16 weeks after irradiation the mice were allocated to receive a thalidomide-containing chow (100 mg/kg body weight/day) or control chow until the end of the experiment. At 40 weeks after irradiation, functional imaging was performed and the hearts were examined for histological damage.

Results: Irradiation led to an increase in epicardial thickness and infiltrating inflammatory cells in the epicardium as well as an increase in interstitial collagen content. The microvasculature had a decreased alkaline phosphatase activity and reduced pericyte coverage. Thalidomide had no protective role in any of these processes. There were no differences in heart function measured between the treatment groups.

Conclusions: Although others have shown protective effects of thalidomide in disease models involving inflammation, fibrosis and blood vessel maturation, thalidomide was not able to reduce radiation-induced heart damage.

Keywords::

• Heart disease
• radiation
• thalidomide