TABLE 2

Effect of probenecid, novobiocin, or MK571 on unidirectional and net fluxes of PAH across the bovine ciliary body in Ussing chambers

The flux values were obtained at t = 2 hours and are the mean ± S.E. of the mean of three separate experiments. The concentration of unlabeled PAH was 1 mM; probenecid and novobiocin were added to the aqueous humor side of the tissue only; MK571 was added to the blood side of the tissue only.

	AH-to-Blood Flux	Blood-to-AH Flux	Net Flux
Control	58.7 ± 10.7	9.4 ± 0.82	49.3 ± 10.2
Probenecid (100 μM)	18.8 ± 3.3^{^a}	16.9 ± 8.3	1.84 ± 8.2^{^a}
Control	41.4 ± 10.8	10.8 ± 1.41	30.6 ± 9.4
Novobiocin (100 μM)	28.8 ± 11.1	28.9 ± 15.2	−0.10 ± 4.6^{^a}
Control	67.6 ± 7.8	16.5 ± 3.6	51.2 ± 10.5
MK571 (100 μM)	26.7 ± 8.7^{^a}	10.5 ± 1.6	16.2 ± 9.3^{^a}

AH, aqueous humor.
↵^a Significantly different from the control, two-tailed unpaired student’s t test; *P < 0.05.