[In situ localization of mRNA gelatinases in cerebral aneurysms].

OBJECTIVE: To explore the role of gelatinases A and B and their tissue inhibitors, TIMP-1 and TIMP-2, in the formation of cerebral aneurysm.
METHODS: In situ hybridization with digoxigenin RNA probes localized cells responsible for gelatinases A and B, TIMP-1 and TIMP-2 mRNA production in histologic sections of aneurysmal (n = 12), and normal (n = 6) cerebral arteries.
RESULTS: The levels of gelatinase B mRNA were found very high in cerebral aneurysms, especially in the site of internal elastic lamella. Gelatinase B mRNA was not found in normal cerebral arteries. Gelatinase A TIMP-1 and TIMP-2 mRNA were not found in both cerebral aneurysms and normal cerebral arteries.
CONCLUSIONS: Differential patterns of expression can be seen in situ, and tissue gelatinase B mRNA levels are elevated in aneurysms, suggesting that gelatinase B maybe responsible for the destruction of internal elastic lamina or even all laminae of cerebral arteries, leading to cerebral aneurysms.