Fluorescein transport in the anterior uvea.
Rabbit ciliary body-iris preparations accumulate 14C-fluorescein against a concentration gradient when incubated in Tyrode's solution at 37 degrees C and pH 7.4 for 1 hr. Under these conditions, fluorescein metabolism is negligible. This accumulation is depressed by cyanide, dinitrophenol, iodoacetate, by incubation in glucose-free medium, and by incubation at 0 degrees C. This uptake is not inhibited significantly by incubation in sodium-free medium, and relatively high concentrations of ouabain are necessary to cause inhibition. Initial uptake studies show saturation kinetics with half-saturation concentration = 0.12 mM and maximum accumulation rate = 2.3 mmoles/hr/kg wet tissue weight. Fluorescein thus appears to accumulate by a carrier-mediated active uptake process. On the basis of series of competition experiments, it is concluded that fluorescein uptake and p-aminohippurate uptake occur by similar, although not identical, mechanisms.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D003486:Cyanides / Q000494:pharmacology; D004140:Dinitrophenols / Q000494:pharmacology; D005452:Fluoresceins / Q000378:metabolism*; D005947:Glucose; D007461:Iodoacetates / Q000494:pharmacology; D007700:Kinetics; D010042:Ouabain / Q000494:pharmacology; D011817:Rabbits; D012964:Sodium; D014602:Uvea / Q000378:metabolism*; D010130:p-Aminohippuric Acid / Q000378:metabolism
D003486:Cyanides; D004140:Dinitrophenols; D005452:Fluoresceins; D007461:Iodoacetates; D010042:Ouabain; D012964:Sodium; D005947:Glucose; D010130:p-Aminohippuric Acid