Figure 2

In vivo imaging of retinal hypoxia in mouse OIR (P13) and age matched room air (RA) pups.

HYPOX-4 was administered systemically to OIR mouse pups 2 hours after return to room air on P12, as well as to age-matched room air pups. In vivo imaging was performed 24 hours post-injection of HYPOX-4. (A) Bright field image of OIR (P13) retina; (B) An image of the same retina in vivo, hypoxia was clearly detected by HYPOX-4 dependent fluorescence within the central avascular retina (green); (C) Bright field image of age-matched RA pup (P13); (D) HYPOX-4 dependent fluorescence was undetectable in aged-matched RA pups; (E) OIR mouse retina showing ex vivo HYPOX-4 dependent fluorescence in the central avascular retina (green); (F) The same retina counterstained with IB4, highlighting the peripheral vascular retina; (G) E and F merged; (H) RA pups showed minimal ex vivo HYPOX-4 dependent fluorescence; IB4 staining of the retinal vasculature (red) from an RA pup; (I) Hypoxia was confirmed in OIR (P12) pups by immunostaining of pimonidazole-adducts (red); blood vessels were counterstained with IB4 (green).