Compared to controls, the volume/micturition was lower in all zymosan-treated CPPS groups (Figure 1a; 0.91±0.23, 0.92±0.09, 0.78±0.11 and 1.62±0.28 ml in Z7, Z14, Z21 and control groups, respectively; control vs Z7, p=0.065; control vs Z14, p=0.066; control vs Z21, p=0.014). The number of micturitions per hour were significantly higher in all CPPS groups, as compared to controls (Figure 1b; 0.95±0.09, 1.08±0.13, 1.18±0.10 and 0.40±0.03 in Z7, Z14, Z21 and control groups, respectively; control vs Z7, p=0.0029; control vs Z14, p=0.0005; control vs Z21, p<0.0001). Similarly, the total number of micturitions during the entire metabolic cage time period were higher in all CPPS groups, as compared to controls (Figure 1c; 15.25±1.44, 17.25±2.06, 18.83±1.62 and 6.40± 0.51 in Z7, Z14, Z21 and control groups, respectively; control vs Z7, p=0.0029; control vs Z14, p=0.0005; control vs Z21, p<0.0001).
Cystometry revealed a significant increase in the number of NVCs in all CPPS groups, as compared to controls (Figure 2a; control vs Z7, p=0.046; control vs Z14, p=0.033; control vs Z21, p=0.014). Similarly, lower bladder compliance was seen in the CPPS groups, as compared to controls. This decrease tended to worsen as the time after zymosan injection proceeded.
Rats with chemically induced CPPS displayed significantly longer voiding times compared to controls. There was also a trend towards longer voiding time as a result of increased time after zymosan injection (Z21 & Z14 > Z7).
There was a tendency towards decreased methacholine-induced contractions in all CPPS groups, as compared to controls (Figure 2b; at 5 µg*kg-1; Z14 vs control, p=0.0023; Z21 vs control, p<0.0001). ATP-induced bladder contractions tended to be lower in the CPPS groups, as compared to controls (Figure 2c; at 100 µg*kg-1; Z7 vs control, p=0.0007; Z14 vs control, p=0.0016; Z21 vs control, p=0.0003).
There were no significant differences between the groups regarding total bladder or prostate weight. However, all zymosan-treated prostate tissues displayed signs of inflammation (avg score 2.2 as compared to 1.0 in controls). Interestingly, while excised bladders from control animals did not show signs of inflammation (avg score 0.5), bladders from zymosan-treated animals did (avg score 1.5).