FIGURE 8.

Post-receptor signaling pathways linked to UTP-Ca²⁺ responses in BON cells. Representative Ca²⁺ responses showing that (A) 100 μM La³⁺, (B) 10 μM 2APB or (C) 1 μM thapsigargin (thaps) can block UTP-induced Ca²⁺transients. In Contrast, (D) RuRed, (E) 20 μM MRS1845 or (F) 10 μM nicardipine are not effective in blocking UTP-induced Ca²⁺ transients. After washing-out the drug (15 min) a partial recovery of the UTP-response was seen for La³⁺ and 2APB but not for thapsigargin (thaps). (G–L) Pooled data for effects of each of the treatments illustrated in (A–F) indicating that La³⁺, 2APB or thaps can abolish Ca²⁺ transients (p < 0.001 for each) whereas RuRed, MRS1845 or Nicardipine did not significantly reduce UTP-induced Ca²⁺ transients (p > 0.05). Table 2 provides detailed description of the inhibitors. The test group involved UTP application followed by UTP + inhibitor in the same cells (with a 10 min recovery time allowed between each drug application. A control group involved two consecutive applications of UTP (p > 0.05 between peaks in two consecutive applications, not shown).