Octreotide inhibits growth factor-induced bovine choriocapillary endothelial cells in vitro

Background: Response to growth factors by the choriocapillaris is one of the main aspects in the development and progression of choroidal neovascularization in age-related macular degeneration (AMD). The aim of the study was to examine the effect of octreotide - an analogue of somatostatin with possible favorable effects in the treatment of age-related macular degeneration - on growth factor-activated bovine choriocapillary endothelial cells (BCEC). Methods: Cultivated BCEC were stimulated with 20 ng/ml VEGF, 5 ng/ml bFGF, 50 ng/ml TGFbeta(2), or 50 ng/ml IGF-I for 24 h. Afterwards, the cells were incubated for a further 24 h with octreotide (10(-6) M). BCEC proliferation was determined by [H-3]-thymidine incorporation. The experiments were performed in normal conditions and in O-2-limited (5% O-2) atmosphere. Results: VEGF, bFGF, and IGF-I significantly stimulated BCEC proliferation under normoxic as well as under hypoxic conditions (P<0.05); the value for TGFbeta(2) stimulation was not significant. Under normoxic conditions, after addition of octreotide to VEGF-, bFGF-, and IGF-I-stimulated cells there was no longer any significant [H-3]-thymidine incorporation compared to the control medium. Under hypoxic conditions similar results were obtained after addition of octreotide to VEGF-, bFGF-, and IGF-I-stimulated cells. Conclusion: Octreotide has inhibitory properties after activation of BCEC with growth factors under normoxic and hypoxic conditions in vitro. Since activation of these cells is a crucial event in the development and progression of AMD, octreotide may be a potential drug for treatment of choroidal neovascularization in these patients.