PACAP Induce Neurite Outgrowth in Cultured Trigeminal Ganglion Cell and Recovery of Corneal enitivity After Flap urgery in Rabbit Original Reearch Article

Purpoe To evaluate the ability of pituitary adenylate cyclae–activating polypeptide (PACAP) to induce growth of neuronal procee in cultured trigeminal ganglion cell, and to accelerate neurite outgrowth and recovery of corneal enitivity after creation of a corneal flap in a rabbit model of laer-aited in itu keratomileui (LAIK) urgery. Deign Animal tudy. Method The cDNA of rabbit PACAP wa equenced, and the expreion of PACAP receptor in the trigeminal ganglia from rabbit wa quantified by quantitative real-time polymerae chain reaction. Trigeminal ganglion cell were iolated from rabbit and cultured for 48 hour with or without PACAP27 (bioactive N-terminal peptide from PACAP). Cell were tained with antibody againt neurofilament, and neurite outgrowth wa quantified by cell counting. In the rabbit LAIK model, a corneal flap with a planned thickne of 130 μm and 8.5 mm diameter wa created with a microkeratome. The rabbit then received eyedrop containing PACAP27 four time a day for eight week, and corneal enitivity wa meaured. Neurite outgrowth wa aeed by taining hitologic ection of the flap area for cholineterae. Reult The deduced amino acid equence of PACAP in rabbit wa identical to that of human. PACAP receptor, PAC1, wa highly expreed in trigeminal ganglia from newborn and adult rabbit. PACAP27 at 1 μM induced growth of neuronal procee in cultured primary trigeminal ganglion cell. In the LAIK model, extenion of neuronal procee from amputated nerve trunk in cornea were oberved after adminitration of eyedrop containing 1 or 10 μM PACAP27. The 10 μM PACAP27 treatment alo greatly accelerated recovery of corneal enitivity. Concluion PACAP may be a candidate drug for ameliorating dry eye after LAIK urgery.