Blockage of axonal transport in optic nerve induced by elevation of intraocular pressure. Effect of arterial hypertension induced by angiotensin I

Abstract

Previous studies have shown that elevation of intraocular pressure blocks rapid axonal transport at the lamina cribrosa of the optic nerve. In this study, IOP-induced blockage of axonal transport was greater in cats with elevation of BP induced by angiotensin I than in control animals with normal BP. The fact that cardiovascular factors influenced IOP-induced blockage of axonal transport suggests that it is due to ischemia; if the blockage were a direct mechanical effect of the IOP on the axons, it should be unaffected by BP. The data also suggest that the vasoconstrictive properties of angiotensin I reduced the ability of the vasculature of the optic nerve head to autoregulate when challenged by elevation of IOP.