Blood barrier in the optic nerve of the hyperglycemic rats

Abstract

The aim of this work was to describe the structure of the optic nerve blood-barrier vessels in control and in hyperglycemic animals. For that purpose, optic nerves from 2 months rats after 6 and 12 weeks citrated buffer or streptozotocin intraperitoneal injected were studied by light and transmis sion electron microscopy. The intraneural vessels were coun- ted, and the endothelial cell and basal lamina were measu- red. Vascular permeability and expression of major histo- compability complex (MHC) class II molecules was explored by immunocytochemistry using antibodies against albumin and Ia OX6, respectively, in both animal groups. Nerve optic vessels from hyperglycemic rats showed: i. endothelial cell and basal lamina thickening matched the control group ii. Keeping pericytes, iii increasing of endothelial cell transcytosis, and iv. Increased number of perivascular macrophagic cells in the vascular wall. We could conclude that the effects of hyperglycemia in the inner vessels of the optic nerve are more similar to those of the cerebral micro- circulation than to those of retinal vessels in hyperglycemic animals.