Figure 1.

Consecutive sections of mouse retina immunoenzymatically stained with antibodies against ET-1 (left) and GFAP (right). The retinal vitreal surface is always shown at the top of the micrographs. A and B: In the normal retina, ET-1 immunoreactivity was only found in astrocytes sparsely distributed along the vitreal surface. GFAP immunostaining labeled similar cell bodies and processes. C and D: These and following images correspond to 0.2 U/μl dispase-injected eyes. One week after injection, the vitreal surface was completely covered by ET-1-immunoreactive astrocyte cell bodies and processes. Irregular ET-1-immunoreactive processes, following a nonradial course, extended into outer layers of the retina (white arrows). GFAP immunolabeled structures along the vitreal surface included astrocytes and Müller endfeet (white arrowhead). Notice the large number of GFAP-immunoreactive processes extending to the outer retinal layers. Most of them followed the typical radial course of Müller cells, but a few resembled endothelinergic processes (white arrows). E and F: Illustration of an inner retinal fold bridged by a small outgrowth (arrows), appearing a week after dispase injection. Strong ET-1 and GFAP immunoreactivities appeared along the vitreal border, within the outgrowth and in retinal processes. GFAP revealed a larger number of processes than ET-1. Immunostained glial cells also surrounded a blood vessel (b). G and H: Retina sections (2 weeks after dispase) showing an outer fold (f). A thin cellular membrane (arrows) attached to the vitreal surface exhibited strong ET-1 and GFAP immunostaining. Elongate ET-1- and GFAP-immunoreactive cells were accumulated along the retinal vitreal surface (asterisk). Immunoreactive processes extended across the retina: few endothelinergic processes reached the invaginated ONL, whereas numerous GFAP-immunoreactive processes appeared close to the subretinal folded surface. Scale bar: 50 μm (A–E, G, H); 25 μm (F).