Abstract
Purpose: :
To investigate the formation of the tight junction of endothelial cells in the capillary of developing rat retina.
Methods: :
The rat retinas were immunostained with monoclonal antisera against zonular occludensa 1 (ZO–1) (1:1,000 Zymed) and occludin (1:250, Zymed), markers of the tight junction between endothelial cells, at postnatal day (P) 7, 9, 10, 11, 14 and 49. For guiding the retinal blood vessels, polyclonal antisera against α–smooth muscle actin (1:1,000, Sigma), a pericyte marker, was used.
Results: :
From P7, the endothelial cells in the ganglion cell layer (GCL) expressed ZO–1 immunoreactivity. But, the endothelial cells in the outer plexiform layer (OPL) began to express ZO–1 immunoreactivity from P10. The expression of ZO–1 was consistent with the time of formation of retinal capillaries. Occludin immunoreactivity was visible in the endothelial cells of the GCL and OPL around P10, although a few occludin immunoreactive endothelial cells occurred in the GCL of the central retinal region at P7.
Conclusions: :
These results suggest that the complete formation of the tight junction in the capillaries might be made from P10 in the developing rat retina.
Keywords: development • vascular cells • cell adhesions/cell junctions