Spatial and Temporal Patterns of SPARC and VEGF Immunoreactivities in the Rabbit Retina in Early Postnatal Life / 대한해부학회지

ABSTRACT

Tissue-derived angiogenic factors are thought to play an important role in angiogenesis. Among these, SPARC and VEGF are known to be involved in physiologic and pathologic angiogenesis. However, the expression of these factors in the rabbit retina, especially in the early postnatal period, remains unclear. To determine whether these factors contribute to retinal angiogenesis in the rabbit retina, expression of SPARC and VEGF was studied by immunohistochemistry at postnatal (P) days 0, 7, 14, and 28. (1) SPARC immunoreactivity was observed in the nerve fiber layer of the medullary ray and the pigment epithelium at all ages. In whole mount preparations, SPARC immunoreactivity was noted in many astrocytes surrounding nerve fibers or blood vessels in the medullary ray. (2) VEGF immunoreactivity of variable intensity was found in ganglion cells, vascular endothelial cells, and some astrocytes. VEGF immunoreactivity was detected from P0, was maintained until P14, and was markedly lower at P28. The spatial pattern of SPARC expression suggests that SPARC functions as a crucial regulator that determines the selective location of the retinal angiogenic process. The temporal pattern of VEGF expression suggests that VEGF is a major angiogenic factor involved in rabbit retinal angiogenesis.