Trimethyltin-induced differential expression of PAR subtypes in reactive astrocytes of the rat hippocampus.

Thrombin, its main inhibitor (protease nexin-1) and its related receptors (protease-activated receptors, PAR-1,-2, -3, -4) were studied in rat hippocampus following administration of trimethyltin (TMT), a neurotoxin inducing neuronal degeneration and reactive gliosis. Reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry revealed that while expression of prothrombin and protease nexin-1 did not change significantly in TMT-treated hippocampi, PARs (in particular PAR-1 and to a lesser extent PAR-2 and PAR-3) were upregulated in reactive astrocytes, suggesting their involvement in neurodegeneration and in the consequent response of the nervous tissue.