Figure 3.

Polyamines increase the [Na⁺]i and decrease the [K⁺]i under capacitation conditions. The graph shows that putrescine induces an increase of the Na+ influx under capacitation conditions (A). On the contrary, under non-capacitation conditions, putrescine induced a decrease of [Na⁺]i; meanwhile, the other polyamines did not induce any meaning change (B). A control to inhibit general Na⁺ channels was performed using 1 μM of amiloride. The graph shows that the presence of all polyamines induced a decrease of the [K⁺]i under capacitation conditions (C) in which spermine was the polymine that induced a marked effect (C). Moreover, under non-capacitation conditions, spermine also induced a decrease of the [K⁺]i (D); nevertheless, putrescine and spermidine induced an increase of [K⁺]i (D). A control to inhibit general K⁺ channels was performed using 1 mM of BaCl₂. Values are the mean ± SEM, n = 3. (*) indicates a meaning difference. Data analysis was performed using Tukey´s multiple comparison test, p < 0.05.