Ontogeny of basic fibroblast growth factor binding sites in mouse ocular tissues

Comparative Study In Vivo and In Vitro of Uniformly 14C‐Labelled and 125I‐Labelled Recombinant Fibroblast Growth Factor 2

“…Exogenous FGF2 stimulates differentiation of retinal cells, and their survival. "'1-FGF2 has been used to identify the binding sites of FGF2 on eye tissue sections (Fayein et al, 1990). The potential receptor sites for FGF2 in the ocular tissues were compared between ['"C]FGF2 and '"I-FGF2.…”

“…In some cases, radioiodinated growth factors were used to visualize specific binding sites on tissue section by microscopic techniques (Fayein et al, 1990). Here, we have also compared [I4C]FGF2 and '*'I-FGF2 in the analysis of binding sites on ocular tissue sections by microscopic techniques.…”

“…The fact that the [''C]FGF2 labelling could be displaced by addition of unlabelled FGF2 confirmed the specificity of the labelling. Binding sites of low affinity were previously localized on the basement membranes (Fayein et al, 1990) corresponding to heparan sulfate proteoglycans. High-affinity receptors were also previously identified on the pigmented epithelium, the inner and outer plexiform layers, and at the level of the inner segments of the photoreceptors.…”

“…Binding of ['"C]FGF2 on tissue sections was studied using the model previously used for 12sI-FGF2 (Fayein et al, 1990). Eyes from 18-day-old mice were fixed with 4 % paraformaldehyde in phosphate-buffered saline (NaCl/P, : 0.05 M sodium phosphate, 0.15 M NaCl, pH 7.4) for 2 h at 4°C.…”

“…Sections of 10 pm were cut at -20°C in a Microtome Bright OTF/AS (DIS), collected on gelatin-coated glass slides, and stored at -20°C. After use, OCT was extracted with NaCU P, and slices were dried for 5 min at room temperature, and incubated for 1 h at 20-22°C in a water-saturated atmosphere with either "7-FGF2 (20 ng/ml, 1 -2X10' c p d n g ; Fayein et al, 1990), or [''C]FGF2 (50 ng/ml) in NaClR, containing 0.1 % BSA. Some incubations were performed with 50ng/ml of [lJC]FGF2 in the presence of either 250-fold excess of unla-1 2 3 4 5 6 7 8 9 10 -18 kDa belled FGF2 (12.5 pg/ml), or soluble heparin (10 pg/ml).…”