Fig. 4.

Shear stress-induced net ATP release from ADPKD cyst cells is greater than from NK cells. Primary NK and PKD cells (5 × 10⁴; A), LTA⁺-NK_TERT and LTA⁺-PKD_TERT cells (B), or DBA⁺-NK_TERT and DBA⁺-PKD_TERT cells (C) were subjected to shear stress at the indicated levels. PKD cells of each type exhibited more net ATP release than did corresponding NK cells at the lowest tested flow. In contrast, PKD cells of each type exhibited far less net ATP release than did corresponding NK cells in response to the highest tested flow. D: hypotonic stress increased net ATP release from primary NK and primary PKD cells (5 × 10⁵ cells). In both isotonic and hypotonic static (no-flow) conditions, net ATP release from primary PKD cells exceeded that from primary NK cells. As noted in the description of the luciferase assay in methods, the values for ATP release into hypotonic (low [Cl⁻]) medium may overestimate ATP release compared with isotonic values by as much as 10% or more. Black bars, NK cells; gray bars, ADPKD cells. *P < 0.05 for PKD or PKD_TERT cells compared with NK or NK_TERT cells in the same condition. #P < 0.05 for cells at intermediate or high shear stress compared with the same cell type at 0.1 dyne/cm².