Movement of fluorescein and fluorescein glucuronide across the isolated rabbit iris-ciliary body.
Movement of fluorescein and fluorescein glucuronide, a fluorescent metabolite of fluorescein, across the isolated iris-ciliary body of the albino rabbit was determined under short-circuit conditions using a modified Ussing's chamber. The permeabilities of this tissue to these dyes were calculated. The outward permeability (from the aqueous to the stromal side) of the iris-ciliary body preparation averaged 6.63 +/- 0.86 for fluorescein and 1.51 +/- 0.47 X 10(-6) cm/sec for fluorescein glucuronide, and the inward permeability (from the stromal to the aqueous side) was 1.68 +/- 0.41 for fluorescein and 1.37 +/- 0.77 X 10(-6) cm/sec for fluorescein glucuronide, respectively. Application of probenecid or ouabain decreased the outward permeability of fluorescein, but it had no significant effect on the fluorescein glucuronide movement. Application of 10(-5) M 2,4-dinitrophenol showed no significant effect on the fluorescein or fluorescein glucuronide movement, but application of 5 X 10(-4) M 2,4-dinitrophenol decreased the outward fluorescein transfer, which was also markedly suppressed by incubation at 0 degrees C. It is possible that an active transport mechanism is involved in the outward fluorescein movement across the iris-ciliary body, while the inward movement of fluorescein and also the fluorescein glucuronide movement across this tissue is mainly by passive diffusion.
Department of Ophthalmology, University of Tokyo School of Medicine, Japan.
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Eguchi
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Araie
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Takase
D019297:2,4-Dinitrophenol; D000818:Animals; D001692:Biological Transport; D002924:Ciliary Body / Q000378:metabolism* / Q000502:physiology; D004140:Dinitrophenols / Q000494:pharmacology; D004553:Electric Conductivity; D005260:Female; D019793:Fluorescein; D005452:Fluoresceins / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D010539:Permeability; D011339:Probenecid / Q000494:pharmacology; D011817:Rabbits
D004140:Dinitrophenols; D005452:Fluoresceins; D010042:Ouabain; C041357:fluorescein glucuronide; D011339:Probenecid; D019297:2,4-Dinitrophenol; D019793:Fluorescein