Inward and the outward permeability of the blood-ocular barrier in monkeys
Nara, Y.; Yoshida, A.
Nippon Ganka Gakkai Zasshi 92(10): 1610-1617
1988
ISSN/ISBN: 0029-0203 PMID: 3213764 Document Number: 312596
We investigated the function of the inward and the outward permeability of the blood-ocular barrier in monkeys by vitreous fluorophotometry (VFP) for making a comparative study of the human eye. The inward permeability (Pin) was calculated by a computer simulation method and the kinetic VFP was performed after fluorescein (F) and the fluorescein monoflucuronide (FG) were injected into the vitreous cavity. The relative ratio of each optical element to the axial length in monkeys was almost equal to that of the human eye. The estimated value of Pin (.times. 10-6 cm/min) was 4.7 .+-. 1.6 and it was similar to the value obtained from the human eye in the same age. The rate of loss from the vitreous body (Kv) of F (0.13 .+-. 0.026) was about four times greater than that of FG (0.030 .+-. 0.009), and the KV of FG was similar to that of sucrose (Kv = 0.04) and that of gentamicin (Kv - 0.035) which have been known to be transported from the vitreous body to the blood by passive transport mechanism. In an additional experiment using intraperitoneal probenecid administration in the same manner, we observed that probenecid caused a marked reduction in the loss from the vitreous body of F but not of FG. Therefore, it was suggested that F is excreted from the eye mainly by active transport in the blood-ocular barrier. The results of comparative studies between Ka and Kv suggested that the active transport is more predominant in the blood-retinal barrier than in the blood-aqueous barrier.