BASIC FIBROBLAST GROWTH FACTOR-LIKE IMMUNOREACTIVITY IN THE RAT BASILAR ARTERY WITH REFERENCE TO COLOCALIZATION WITH NADPH-DIAPHORASE IN THE TRIGEMINAL GANGLION

The location of basic fibroblast growth factor (bFGF)-like immunoreact ivity and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphora se (neuronal nitric oxide synthase) activity in the rat basilar artery and in the trigeminal, sphenopalatine and superior cervical ganglia w as investigated. bFGF immunoreactivity was seen mainly in adventitial nerve fibers of the rat basilar artery, but not in the endothelium. El ectron microscopy of the tunica media showed a number of immunoreactiv e nerve endings in the vicinity of local smooth muscle cells. Among th e cranial ganglia that innervate the basilar artery, only the trigemin al ganglion had bFGF-immunoreactivity neurons. Nerve cells and fibers with NADPH-diaphorase activity were detected in the basilar artery and in the sphenopalatine and trigeminal ganglia, and the co-localization of bFGF and NADPH-diaphorase was noted only in the trigeminal ganglio n. Furtheremore, Fluoro-gold tracing in combination with bFGF immunohi stochemistry demonstrated that bFGF-containing nerve fibers in the wal l of the basilar artery arise from the trigeminal ganglion. These find ings provide a morphological basis for the nitric oxide-mediated dilat ation of cerebral arteries by bFGF.