- Seki T, Hinohara Y, Taki C, Nakatani M, Ozawa M, Nishimura S, et al. PACAP stimulates the release of interleukin-6 in cultured rat Müller cells. Ann N Y Acad Sci. 2006;1070:535-9 pubmed..These data suggest that Müller cells are one of the target cells for PACAP, stimulating the release of IL-6, and providing a mechanism whereby PACAP exerts a significant neuroprotective effect in the retina. ..