Alteration of thrombospondin-1 and -2 in rat brains following experimental intracerebral hemorrhage

Object. Spontaneous intracerebral hemorrhage (ICH) is among the most intractable forms of stroke. Angiogenesis, an orchestrated balance between proangiogenic and antiangiogenic factors, is a fundamental process to brain development and repair by new blood vessel formation from preexisting ones and can be induced by ICH. Thrombospondin (TSP)-1 and TSP-2 are naturally occurring antiangiogenic factors. The aim of this study was to observe their expression in rat brains with ICH. Methods. Intracerebral hemorrhage was induced in adult male Sprague-Dawley rats by stereotactic injection of collagenase VII or autologous blood into the right globus pallidus. The expression of TSP-1 and -2 was evaluated by immunohistochemistry and quantitative real-time reverse transcription polymerase chain reaction analysis. Results. After the induction of ICH, some TSP1- or TSP2-immunoreactive microvessels resided around the hematoma for similar to 7 days and extended into a clot thereafter. Cerebral endothelial cells expressed the TSPs. The expression of TSP-1 and TSP-2 mRNA peaked at 4 and 14 days after collagenase-induced ICH, respectively. Conclusions. Findings in this study suggest that ICH can alter the expression of TSP-1 and TSP-2, which may be involved in modulating angiogenesis in brains following ICH. (DOI: 10.3171/2010.1.JNS09637)