Loss of sympathetic innervation caused a significant increase in steady state mRNA levels of fibronectin and a 15% increase in laminin-ß1 mRNA 3 weeks after surgical sympathectomy. Protein expression also increased at this point. In addition, capillary basement membrane thickness increased significantly. NG2 proteoglycan staining decreased significantly in pericytes in the sympathectomized rat retina. Steady state mRNA for PDGF-BB decreased significantly 6 weeks after surgery.
Sympathetic nerves may be compromised in diabetes, and these findings suggest that they may regulate some complications of diabetic retinopathy. Gene expression levels of fibronectin and laminin-ß1 changed between 1 and 3 weeks. These data are supported by electron microscopy, which showed the increase in basement membrane thickness in vivo. Loss of sympathetic innervation to the eye also caused a decrease in the number of pericytes. Steady state mRNA expression of PDGF-BB was reduced, suggesting a mechanism for the loss of pericytes in the sympathectomized retina. Overall, these results suggest that sympathetic nerve alterations may function in some complications observed in diabetic retinopathy, and this may be a suitable model to investigate therapies for this disorder.
(Investigative Ophthalmology and Visual Science. 2005;46:744-748.)
© 2005 by The Association for Research in Vision and Ophthalmology, Inc.
DOI: 10.1167/iovs.04-1023