CELLULAR-LOCALIZATION OF ENDOTHELIN RECEPTOR MESSENGER-RNAS (ET(A) AND ET(B)) IN BRAIN-TUMORS AND NORMAL HUMAN BRAIN

We performed in situ hybridization (ISH), using radioactively labeled deoxyoligonucleotides, to localize endothelin (ET) receptor subtype mR NAs (ET(A) and ET(B)) in a series of meningiomas in comparison to norm al human meninges. Our examination also addressed the cerebellum adjac ent to the meninges investigated. Tumor cells of all meningiomas exami ned showed strong hybridization signals for ET(A) receptor mRNA, where as for ET(B) receptor mRNA only weak hybridization signals could be de tected in endothelial cells of tumor blood vessels and in some cell cl usters. mRNAs for neither ET receptor were detectable in normal leptom eninges. In human cerebellum we found ET(A) receptor mRNA only in larg e blood vessels; ET(B) receptor mRNA was intensely expressed in Bergma nn glial cells. Neither subtype was detectable in neurons.