Ocular diseases such as proliferative diabetic retinopathy are the major cause of blindness in industrialized countries. The main pathologic features of these diseases are hypoxia and overproduction of growth factors resulting in pathologic proliferation of endothelial cells and new vessel formation. Particularly, hypoxia and growth factors, such as VEGF, IGF-1, bFGF and TGF beta(2), show a complex interaction in the onset and progression of the diseases. Therefore, to date, most therapeutic strategies for proliferative retinopathies have targeted proliferation of endothelial cells evoked by growth factors. Recently, a synthetic analog of somatostatin, octreotide, has been shown to inhibit the proliferation of various cells in vitro, including endothelial cells. In this study, we have investigated the proliferative response of bovine retinal endothelial cells (BREC) to growth factors under hypoxic conditions and the modulation by octreotide. We found a dose-dependent increase of cell proliferation with VEGF, IGF-1 and bFGF, and inhibition of hypoxia-induced cell proliferation with TGF beta(2). Moreover, growth factor-induced, but not hypoxia-induced, cell proliferation was attenuated in the presence of octreotide. In contrast, TGF beta(2) abolished hypoxia-induced BREC proliferation. Similar to octreotide BIM23027, a somatastatin receptor subtype 2 (SSTR2) receptor agonist was able to attenuate the growth factor-induced proliferation of BREC expressing mRNA and protein for SSTR2. Therefore, we postulate that octreotide exerts its effects mainly through binding to the SSTR2. Taken together, our findings point to octreotide as a promising candidate for the treatment of eye disorders involving growth factor-dependent proliferation of endothelial cells.

This article has been cited by other articles:

				N. Mastrodimou, F. Kiagiadaki, and K. Thermos The Role of Nitric Oxide and cGMP in Somatostatin's Protection against Retinal Ischemia Invest. Ophthalmol. Vis. Sci., January 1, 2008; 49(1): 342 - 349. [Abstract] [Full Text] [PDF]

				E. Carrasco, C. Hernandez, A. Miralles, P. Huguet, J. Farres, and R. Simo Lower Somatostatin Expression Is an Early Event in Diabetic Retinopathy and Is Associated With Retinal Neurodegeneration Diabetes Care, November 1, 2007; 30(11): 2902 - 2908. [Abstract] [Full Text] [PDF]

				M. D. Monte, M. Cammalleri, D. Martini, G. Casini, and P. Bagnoli Antiangiogenic Role of Somatostatin Receptor 2 in a Model of Hypoxia-Induced Neovascularization in the Retina: Results from Transgenic Mice Invest. Ophthalmol. Vis. Sci., August 1, 2007; 48(8): 3480 - 3489. [Abstract] [Full Text] [PDF]

				C. Hernandez, E. Carrasco, R. Casamitjana, R. Deulofeu, J. Garcia-Arumi, and R. Simo Somatostatin Molecular Variants in the Vitreous Fluid: A comparative study between diabetic patients with proliferative diabetic retinopathy and nondiabetic control subjects Diabetes Care, August 1, 2005; 28(8): 1941 - 1947. [Abstract] [Full Text] [PDF]