Vasoactive intestinal peptide (VIP) like peptides in the cerebral circulation of the cat

Neurobiology in primary headaches

“…PACAPimmunoreactivity and PACAP mRNA have been found in the sphenopalatine and otic ganglia [194]. Perivascular nerve fibers that contain PACAP immunoreactivity can be seen in cerebral blood vessels and PACAP mediates dilatation [107,168,192]. The majority of the PACAP-immunoreactive nerve fibers constitute a subpopulation of fibers containing VIP/NOS immunoreactivity as verified by tracing, denervation and co-localization experiments [47].…”

“…One possible explanation is that additional substances are released together with ACh to mediate dilatation [122,123,164]. [83,107,192]. In fact it has been suggested that NO might be the last link in cholinergic transmission.…”

“…PACAP dilates cerebral arteries and can increase cerebral blood flow [107,168,192]. Activation of the trigeminovascular system results in co-release of CGRP and PACAP into the jugular vein of the cat [204], a model used in studies of migraine [78].…”

Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery

“…In the brainstem, VIP-positive cells are present in the mesencephalic periaqueductal gray and the dorsal and linear raphe nuclei, whereas PACAP neurons are abundant in the PVN and the dorsal vagal complex. In contrast, both PACAP and VIP-immunoreactive fibers seem to innervate the wall of cerebral blood vessels (Jansen-Olesen et al, 1994).…”

“…PACAP has also been found to stimulate the production of vascular endothelial growth factor, which plays an important role in angiogenesis and vascular permeability (Gloddek et al, 1999). The vasodilatory effect of PACAP is associated with a dose-dependent increase in blood flow in various organs (Nandha et al, 1991;Ishizuka et al, 1992;Minkes et al, 1992a;Warren et al, 1992a,b;Naruse et al, 1993;Santiago and Kadowitz, 1993;Mirfendereski et al, 1997;Whalen et al, 1999a,b,c), including brain Jansen-Olesen et al, 1994;Seki et al, 1995a;Ohtaki et al, 2004), and a decrease in mean arterial blood pressure (Ishizuka et al, 1992;Carlsson et al, 1996;Mirfendereski et al, 1997;Ohtaki et al, 2004). Altogether, these observations highlight the major vasorelaxant effect of PACAP and indicate that this neuropeptide may have a potential therapeutic value for the treatment of hypertension.…”