Figure 1. A set of microphotographs and a graph documenting inhibition of 5 mM CoCl₂-derived increased angiogenesis of hyaloid-retinal vessels (HRVs) (asterisk) resulting from co-treatment with dopaminergic agonists in 3 dpf Tg(Fli-1:EGFP) zebrafish larvae. (a) The control untreated larva; HRVs are marked with *. (b) 5 mM CoCl₂ exposure resulted in increased HRVs branching. (c–g) Co-treatment with 2.5 µM/L bromocriptine, 2.5 µM/L cabergoline, 2.5 µM/L pergolide and 2.5 µM/L bevacizumab, respectively, resulted in significant inhibition of HRVs abnormal branching. (g) The graph presenting the kappa coefficient (ĸ) values (ratio of HRVs area to eyeball area) in investigated groups. (one-way ANOVA, GraphPad Prism 5, *** p < 0.001).

Figure 2. A set of microphotographs and a graph documenting inhibition of 5 mM CoCl₂-derived abnormal angiogenesis of intersegmental vessels (ISVs) resulting from co-treatment with dopaminergic agonists in 3 dpf Tg(Fli-1:EGFP) zebrafish larvae. (a) The control untreated larva presented normal morphology and distribution of ISVs; (b) 5 mM CoCl₂ exposure promoted increased protrusive/regressive activity (arrowhead), branching (arrow) and swelling (asterisk). (c–f) Co-treatment with 2.5 µM/L bromocriptine, 2.5 µM/L cabergoline, 2.5 µM/L pergolide and 2.5 µM/L bevacizumab, respectively, resulted in significant inhibition of improper ISVs development. (g) The graph presenting the number of all abnormalities found in investigated groups (one-way ANOVA, GraphPad Prism 5, *** p < 0.001; ** p < 0.01). PCV—posterior cardinal vein; DA—dorsal aorta; ISV—intersegmental vessel; DLAV—dorsal longitudinal anastomotic vessel.

Figure 3. Expression profiles of zebrafish vegfaa, vegfr1 and vegfr2 genes. The graphs show data of the mRNA expression of (a) vegfaa, (b) vegfr1 and (c) vegfr2 from pooled 72-h post-fertilization (hpf) wild-type zebrafish larvae (n = 30) in six experimental groups: (1) control, (2) exposed to 5 mM CoCl₂; (3) exposed to a mixture of 5 mM CoCl₂ and 2.5 µM/L bromocriptine; (4) exposed to a mixture of 5 mM CoCl₂ and 2.5 µM/L cabergoline; (5) exposed to a mixture of 5 mM CoCl₂ and 2.5 µM/L pergolide; and (6) exposed to a mixture of 5 mM CoCl₂ and 2.5 µM/L bevacizumab. Each group was covered by samples analyzed in triplicate in three separate experiments. Data in the figure represent the average of the three individual experiments. Gene expression values were normalized to housekeeping gene ef1-α; 5 mM CoCl₂ exposure resulted in significant upregulation of the expression of vegfaa in comparison to the control group (a). Co-treatment with 2.5 µM/L bromocriptine, 2.5 µM/L cabergoline, 2.5 µM/L pergolide and 2.5 µM/L bevacizumab resulted in a statistically significant decrease in the expression of previously up regulated vegfaa (a). The expression of vegfr1 and vegfr2 were not altered by both 5 mM CoCl₂ treatment and dopaminergic agonists’ co-treatment in comparison to the control (b). (One-way ANOVA, GraphPad Prism 5, *** p < 0.001; ** p < 0.01; * p < 0.05; ns: not statistically significant differences (p > 0.05)).

Figure 4. Expression profiles of zebrafish pgfa, pgfb, fgf2, tgfb1, igf2a and igf2b genes. The graphs show data of the mRNA expression of (a) pgfa, (b) pgfb, (c) fgf2, (d) tgfb1a, (e) igf2a and (f) igf2b from pooled 72-h post-fertilization (hpf) wild-type zebrafish larvae (n = 30) in six experimental groups: (1) control; (2) exposed to 5 mM CoCl₂; (3) exposed to a mixture of 5 mM CoCl₂ and 2.5 µM/L bromocriptine; (4) exposed to a mixture of 5 mM CoCl₂ and 2.5 µM/L cabergoline; (5) exposed to a mixture of 5 mM CoCl₂ and 2.5 µM/L pergolide; and (6) exposed to a mixture of 5 mM CoCl₂ and 2.5 µM/L bevacizumab. Each group was covered by samples analyzed in triplicate in three separate experiments. Data in the figure represent the average of the three individual experiments. Gene expression values were normalized to housekeeping gene ef1-α; 5 mM CoCl₂ exposure resulted in significant downregulation of the expression of all the above-mentioned genes in comparison to the control group (a–f). Co-treatment with 2.5 µM/L bromocriptine, 2.5 µM/L cabergoline, 2.5 µM/L pergolide and 2.5 µM/L bevacizumab resulted in a statistically significant increase of the expression of previously up downregulated pgfa and pgfb (a,b). Co-treatment with dopaminergic agonists has varied influence on genes encoding the chosen growth factors (see detailed description in the text) (c–g). (One-way ANOVA, GraphPad Prism 5, *** p < 0.001; ** p < 0.01; * p < 0.05; ns: not statistically significant differences (p > 0.05)).