Assessment of the permeability of the blood-retinal barrier in hypertensive rats.
We assessed the permeability surface area products at the blood-retinal barrier and blood-brain barrier to sucrose (molecular weight, 340) and microperoxidase (molecular weight, 2000) following acute hypertension induced by metaraminol in Wistar-Kyoto rats (controls) and during chronic hypertension in spontaneously hypertensive rats. In acute hypertension, the permeability surface area product for sucrose was increased at the blood-retinal barrier and at the blood-brain barrier over control values (p less than 0.02), and the vessels became leaky to microperoxidase. In chronic hypertension, the permeability of the blood-retinal barrier to sucrose was increased over that in control animals (p less than 0.02), whereas the permeability of the blood-brain barrier was unaffected. Neither barrier leaked microperoxidase. These results indicate that the blood-brain barrier and the blood-retinal barrier are similarly affected in acute hypertension and that in chronic hypertension, the blood-brain barrier is unaffected whereas the blood-retinal barrier is rendered more permeable to small, but not large, solutes.
D000208:Acute Disease; D000818:Animals; D001812:Blood-Brain Barrier; D001813:Blood-Retinal Barrier; D002908:Chronic Disease; D006973:Hypertension / Q000139:chemically induced / Q000235:genetics / Q000503:physiopathology*; D008680:Metaraminol; D010539:Permeability; D010544:Peroxidases / Q000493:pharmacokinetics; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013395:Sucrose / Q000493:pharmacokinetics
D013395:Sucrose; D008680:Metaraminol; D010544:Peroxidases; C021799:microperoxidase