Spermidine Oxidation-Mediated Degeneration of Retinal Pigment Epithelium in Rats

Figure 4

Spermidine-induced degeneration of retinal pigment epithelium (RPE) and photoreceptor cells in rats. Cross-sections of rat eyes were prepared (a, b) 1 day after the administration of DPBS, (c–l) 1, 3, 7, 14, and 28 days after the intravitreal administration of spermidine (20 nmol/eye), and (m–o) 7 days after the injection of spermidine (10 or 30 nmol/eye). Black and white scale bars indicate 50 and 20 μm, respectively. Red arrows in (d) indicate RPE cell vacuolization. Red arrows in (f), (h), and (p) indicate RPE cell degeneration. Red arrows in (j) and (l) indicate RPE cell regeneration. Yellow arrows in (h), (j), (l), and (p) indicate photoreceptor cell degeneration. NFL-GCL: nerve fiber layer and ganglion cell layer. IPL: inner plexiform layer. INL: inner nuclear layer. OPL: outer plexiform layer. ONL: outer nuclear layer. IS: inner segment. OS: outer segment. RPE: retinal pigment epithelium. C: choroid.

(a) Control, day 1-1

(b) Control, day 1-2

(c) 20 nmol/eye, day 1-1

(d) 20 nmol/eye, day 1-2

(e) 20 nmol/eye, day 3-1

(f) 20 nmol/eye, day 3-2

(g) 20 nmol/eye, day 7-1

(h) 20 nmol/eye, day 7-2

(i) 20 nmol/eye, day 14-1

(j) 20 nmol/eye, day 14-2

(k) 20 nmol/eye, day 28-1

(l) 20 nmol/eye, day 28-2

(m) 10 nmol/eye, day 7-1

(n) 10 nmol/eye, day 7-2

(o) 30 nmol/eye, day 7-1

(p) 30 nmol/eye, day 7-2