Fig. 6.

The magnitude of bladder contractions evoked by DNP stimulation were strongly correlated with bladder volume before (A) and after (B) bilateral hypogastric nerve transection. The magnitudes of DNP stimulation-evoked bladder contractions were determined at 1-cc volume intervals between the stimulation-evoked contraction volume threshold and suprathreshold volumes. Contraction magnitudes were normalized by scaling between 0 (minimum value) and 1 (maximum value). A, left: normalized mean contraction pressures as a function of normalized bladder volume; right: regression lines (linear or quadratic) for the relationship between bladder volume and mean contraction magnitude for each cat. A significant correlation was found between mean contraction magnitude and bladder volume for all 3 cats investigated (P < 0.0001, Cat 1: r = 0.8518, n = 3; Cat 2: r = 0.8480, n = 7; Cat 3: r = 0.8708, n = 4). B: after bilateral hypogastric nerve transection. Left: normalized maximum contraction magnitudes as a function of normalized bladder volume. Right: regression lines (linear or quadratic) for the relationship between bladder volume and maximum contraction magnitude for each cat. A significant correlation was found between maximum contraction magnitude and bladder volume for all 3 cats investigated (P < 0.0001, Cat 1: r = 0.8893, n = 3; Cat 2: r = 0.8687, n = 7; Cat 3: r = 0.8688, n = 4).