Figure 6. ZD7288 does not inhibit the increases in [Na⁺]_i and [Ca²⁺]_i induced by speract, but significantly slows the rate of [Na⁺]_i uptake.

Sperm were loaded with SBFI AM (A) and fluo-3 AM (B), as indicated in Methods. Cells were incubated with ZD7288 (300 μm) for 10 min, after which speract (100 nm) was added (A and B). There was no difference in the normalized [Na⁺]_i (C) and [Ca²⁺]_i (D) changes (Δ) induced by speract between control and ZD7288-treated conditions. Each condition represents the mean ± s.e.m. (n > 6). The kinetic constants are given in Table 3.