Abstract
It is well known that matrix metalloproteinase (MMP) families, especially MMP-2 and MMP-9, play an important role in progression of saccular cerebral aneurysms. However, the functions of MMP-2 and MMP-9 have not been reported for the early stage of progression of saccular cerebral aneurysms in detail. Clarification of the production mechanism for cerebral aneurysms is needed for further improvement of remedies against cerebral aneurysms. Thus, expression of MMP-2 and MMP-9 in the early stage of cerebral aneurysms was investigated by RT-PCR and immunostaining with anti-MMP-9 antibody to cereberovasculature of rats that had cerebral aneurysm induced by ligation of left common carotid artery.
MMP-2 gene was constitutively expressed at the anterior cerebral artery-olfactory artery junction regardless of whether ligation of the left common carotid artery was performed or not. MMP-9 gene was expressed at the anterior cerebral artery-olfactory artery junction on the non-ligated side 4 weeks after the operation. These results suggest that continuous expression of MMP-2 gene is independent of cerebral aneurysm inducing factors and that MMP-9 gene is expressed during the progression of cerebral aneurysms. Therefore, it is possible that MMP-9 participates in the formation of cerebral aneurysms while MMP-2 is expressed continuously.
