Fig. 10.

Effect of the phospholipase C inhibitor U73122 (A) and its inactive analog U73343 (B) on the adenosine (ADO)-induced inhibition of [¹⁴C]oxalate uptake by Caco2-BBE (C2) cells. A: C2 cells were preincubated with vehicle (Control), 100 µM ADO (ADO) for 2 min, 5 µM U73122 for 30 min followed by 100 µM ADO with continued presence of U73122 (ADO + U73122) for 2 min, or 5 µM U73122 (U73122) alone for 32 min and then [¹⁴C]oxalate uptake was measured as described in materials and methods. Values are means ± SE of 5 independent experiments each of which was done in triplicate and was normalized to the respective Control value. U73122 completely and significantly blocked the inhibition induced by ADO (*P < 0.05 for ADO compared with Control and ADO + U73122, by ANOVA). B: C2 cells were preincubated with vehicle (Control), 100 µM ADO (ADO) for 2 min, 5 µM U73343 for 30 min followed by 100 µM ADO with continued presence of U73343 (ADO + U73343) for 2 min, or 5 µM U73343 (U73343) alone for 32 min and then [¹⁴C]oxalate uptake was measured as described in materials and methods. Values are means ± SE of 5 independent experiments each of which was done in triplicate and was normalized to the respective Control value. U73343 had no significant effect on the inhibition induced by ADO. *P < 0.001 and < 0.05 for Control compared with ADO and ADO + U73343, respectively, by ANOVA.