Uptake of [14C] adenosine into primary cultured sheep CPEC. The panel shows the cellular uptake from the apical (upper) chamber as a donor (left side) and from the basolateral (lower) chamber as a donor (right). Values shown represent uptake of adenosine, corrected for tracer trapped in the extracellular space, after 5 or 10 min of incubation in the uptake buffer containing [14C] adenosine and [3H] mannitol in the donor chamber. Data are shown for uptake under control conditions in Na+-containing medium (black bars), using Na+-free uptake buffer (grey bars), or in uptake buffer containing both Na+ and 1 uM NBTI (open bars). All values are presented as mean ± SEM from three to five separate inserts obtained from at least two separate isolations. Statistical significance: n.s., P > 0.05 vs. control; **P < 0.01 vs. control by ANOVA.