The present study aimed to identify the characteristics and physiological function of the P2Y₁₁ receptor, a receptor likely expressed in human retinoblastoma cells.

We measured possible P2Y₁₁ signaling in WERI-Rb-1 cells using a Ca²⁺ imaging technique and RT-PCR.

1) 10 µM ATP elicited a strong but transient increase in Ca²⁺ in the WERI-Rb-1 cells, and this Ca²⁺ rise was well maintained after external Ca²⁺-depletion. 2) ATP-induced Ca²⁺ response arose entirely through Ca²⁺ mobilization. 3) P2Y₁₁ agonist (BzATP, 100 µM) increased Ca²⁺ by 31.2±3.7 % of ATP effect. 4) mRNA for P2Y11 subtype was identified using RT-PCR.

P2Y₁₁ purinergic activation can increase the intracellular calcium level through calcium mobilization in undifferentiated retinoblastoma cells, which may play an important role in cell proliferation, differentiation, and even pathologic processes.