抄録
We examined whether Y-39983, a novel ROCK inhibitor, and Y-27632 can make injured RGC axons regenerate into the crushed optic nerve (OpN) of adult cats. Small pieces of the cat retina were cultured in medium containing Y-27632 or Y-39983 for 14 days. After fixation, the neurites were stained with anti-TUJ-1 antibody. Number and length of TUJ-1 positive processes were obtained. Microcrush of optic nerve (OpN): The left OpN of anesthetized cats was tied up and crushed. Y-39983 or PBS was injected into the vitreous and the crush site. Anterograde labeling of regenerated axons: 2 days after a WGA-HRP injection into the vitreous, the cats were deeply anesthetized, perfused with fixation on day 14. The OpN was sectioned in a cryostat, reacted for HRP with TMB. Retinal culture: To obtain the optimum concentration for axonal regeneration, we examined effect of Y-27632 and Y-39983 on neurite outgrowth of cultured retinal pieces. On day 14 the number of TUJ-1 positive processes was maximum in the culture containing 3 and 10 μM Y-39983: the number was greater than that in 10-100 μM Y-27632. No neurites protruded in culture containing 30 μM Y-39983 or 1 mM Y-27632. Axonal regeneration in crushed OpN:From the culture results we injected Y-39983 at 10 and 100 μM. An injection of 10 μM Y-39983 increased regenerated axons longer than 0.5 mm from the crush site. Second injection of 10 μM Y-39983 at day 7 increased the number 2 fold at 0.5 mm, 3.5 fold at 2 mm than in one injection of 10 μM Y-39983. ROCK inhibitor, Y39983, enabled injured axons of RGCs of adult cats to regenerate into the crushed OpN. [J Physiol Sci. 2007;57 Suppl:S29]
