Clinical management of proliferative diabetic retinopathy has changed very little
in the last 5 decades, relying primarily on laser ablation of the retinal vasculature.
Several lines of clinical and experimental evidence suggest that somatostatin analogues
may be efficacious in inhibiting neovascularization associated with proliferative
retinopathy but the mechanism of action for these compounds is unclear. Inhibition
of growth hormone secretion and the subsequent suppression of insulin-like growth
factor 1 (IGF-1) production by somatostatin has been suggested as the mechanism of
action, however, in vitro studies suggest that somatostatin analogues suppress endothelial cell growth through
a direct, somatostatin receptor-mediated inhibition of pro-survival signaling pathways.
The advent of a new generation of modified peptide and peptidomimetic somatostatin
analogues has allowed investigators to more carefully define the receptor subtypes
responsible for somatostatin-induced endothelial cell death and may eventually lead
to the clinical development of somatostatin analogues that can reduce endothelial
cell proliferation, independent of suppression of circulating hormone levels.
Key words:
Diabetic Retinopathy - Somatostatin - Octreotide - Apoptosis - Insulin-Like Growth
Factor - Growth Hormone - Angiogenesis
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M. B. Grant
Department of Pharmacology and Therapeutics
University of Florida College of Medicine
P. O. Box 100267
Gainesville, Fl 32610
USA
eMail: E-mail:grantma@pharmacology.ufl.edu
