Extracellular ATP plays an important role in the regulation of renal function. However, the effect of ATP on Na⁺/glucose cotransporter has not been elucidated in proximal tubule cells. Therefore, this study was performed to examine the action of ATP on Na⁺/glucose cotransporter and its related signal pathways in primary cultured rabbit renal proximal tubule cells (PTCs). ATP increased [¹⁴C]--methyl-D-glucopyranoside (-MG) uptake in a time (> 1 hr) and dose (> 10^-6 M) dependent manner. ATP stimulated -MG uptake by an increase in V_max without affecting the K_m. ATP-induced increase of -MG uptake was correlated with the increase of both SGLT1 and SGLT2 protein expression levels. ATP-induced stimulation of -MG uptake was blocked by suramin (non specific P2 receptor antagonist), RB-2 (P2Y receptor antagonist), and MRS 2179 (P2Y1 receptor antagonist), suggesting a role of P2Y receptor. ATP-induced stimulation of -MG uptake was blocked by pertussis toxin (PTX, G_i protein inhibitor), SQ 22536 (adenylate cyclase inhibitor), and [protein kinase A (PKA) inhibitor amide 14/22] (PKI). ATP also increased cAMP formation, which was blocked by PTX and RB-2. However, pretreatment of adenosine deaminase did not block the ATP-induced cAMP formation. In addition, ATP-induced stimulation of -MG uptake was blocked by SB 203580 [p38 mitogen activated protein kinase (MAPK) inhibitor], but not by PD 98059 (p44/42 MAPK inhibitor) and SP 600125 (JNK inhibitor). Indeed, ATP induced phosphorylation of p38 MAPK. In conclusion, ATP increases -MG uptake via cAMP and p38 MAPK in renal proximal tubule cells.