An adenosine agonist regulates outward active transport of fluorescein across rabbit blood retinal barrier

ACADEMIC PRESS, Kawahara, A; Hikichi, T; Kitaya, N; Takahashi, J; Mori, F; Yoshida, A, EXPERIMENTAL EYE RESEARCH, 80(4), 493-499, 2005. authorPURPOSE. To investigate the regulation of an adenosine agonist, 2-5’-N-ethylcarboxamidoadenosine (NECA) on the outward active transport of fluorescein across rabbit blood retinal barrier (BRB).METHODS. Pigmented rabbits were given an intravitreous injection of various concentrartions of NECA or phosphate buffered saline (PBS). Sodium fluorescein was intravenously injected 180 minutes after NECA injection. Differential vitreous fluorophotometry (DVF) was performed 180 minutes after intravenous injection of sodium fluorescein to measure fluorescein (F) and fluorescein monoglucuronide (FG) concentrations in the vitreous. The F/FG ratio was calculated as an indicator of the estimated outward active transport of the BRB. Retinal detachments were experimentally produced by injection of PBS into the subretinal space. Experimental solution or PBS were injected intravitreally, and the size of blebs was monitored under masked conditions.RESULTS. In eyes with intravitreal injection of high dose NECA, F/FG ratio was significantly lower when compared with in controls (p<0.05), but in eyes with low dose injection that was higher (p