RESUMO
Objective:To investigate the changes in the morphology, structure and function of the bladders and their effects on the upper urinary tract dilatation(UUTD) after lumbosacral nerve transecting in rats.Methods:A total of 45 female SD rats were included, randomly divided into 3 groups with 15 rats in each group. Two groups were performed bilateral lumbar 6(L6) and cauda equina nerve shearing to establish neurogenic bladder(NB) model, which were nerve transected for 4 weeks(NB-4W) group and nerve transected for 12 weeks(NB-12W) group. Another group was performed bilateral L6 nerves and cauda equine exposing but not transecting, which was sham-operation (Sham) group. Cystometry and renal ultrasound examination were performed and rats in each group were killed to collect the kidney and bladder tissues in NB-4W group at 4 weeks, in Sham group and NB-12W group at 12 weeks after operation. HE, Masson staining, immunohistochemical staining and western blot were used to detect histological changes, expression of transforming growth factor-β1(TGF-β1) and α-smooth muscle actin(α-SMA).Results:All rats in NB-4W and NB-12W group showed acontractile detrusor. In the NB-4W and NB-12W group, the maximum cystometric capacity [(5.84±0.33) ml and (3.13±0.35) ml], the detrusor leak point pressure [(25.41±0.86) cm H 2O and (27.36±2.04) cm H 2O] (1 cm H 2O = 0.098 kPa), were significantly higher than those in the Sham group [(0.98±0.14) ml, (7.13±0.90) cm H 2O, both P<0.05]. Compliance in NB-4W group [(0.28±0.21) ml/cm H 2O] and NB-12W group [(0.17±0.12) ml/cm H 2O] were significantly lower than that of the Sham group [(0.34±0.26) ml/cm H 2O], and the compliance of NB-12W group was lower than that of NB-4W group significantly (all P<0.05). HE staining of the bladder showed that the inflammatory cell infiltration was obvious in the NB-4W and NB-12W group. Bladder collagen volume fractions in NB-4W group [(30.5±1.5) %] and NB-12W group [(45.2±3.8) %] were both higher than that of Sham group [(20.7±2.2) %, both P<0.05]. The expression of TGF-β1 and α-SMA in the bladder tissue of NB-4W group were higher than those of sham group, and that of NB-12W group were higher than NB-4W group. In NB-4W group and NB-12W group, 3 (20.0 %) and 7 (46.7 %) rats were found hydronephrosis, respectively. Additionally, HE staining showed that the degree of renal tubule injury and the number of inflammatory cell infiltration in the NB-4W and NB-12W group were higher than those in the Sham group. Masson staining showed that the volume fraction of collagen in kidneys of NB-4W and NB-12W group were (13.1±1.4) % and (21.6±1.9) %, respectively, which were significantly higher than that in sham operation group [(4.6±0.7) %, both P<0.05]. Conclusions:Bilateral L6 + cauda equina nerve transecting can induce NB with hydronephrosis in parts of rats. The degree of bladder fibrosis gradually increased with the time of nerve transection, and the incidence and severity of UUTD also increased with the time of nerve transection.
RESUMO
Objective:To investigate the effects and mechanism of cystostomy on young rats′ bladders function.Methods:Eighty female SD rats were divided into cystostomy group, sham operation group (the two groups included day 1, 3, 5 after operation), control group(it included day 1, 3, 5 after operation) and medicine intervention group by using random number table, there were 8 rats in each group.Cystometry was conducted in cystostomy group (day 1, 3, and 5 postoperative subgroup), and voided interval (VI), voided volume (VV), postvoid residual urine (PVR), bladder capacity (BC), maximum bladder pressure (Pves.max), bladder threshold pressure (Pves.thr), and bladder compliance(△C) were recorded.The rats in sham operation and control groups voided freely in the condition of diuresis by intravenous infusion saline, and VV, PVR and BC were recorded.Bladders′ tissues were collected for HE staining and histopathological inflammation scores (HIS) after urodynamic investigations.In medicine intervention group, different doses of anisodamine were applied and the changes of VI, VV, PVR, BC, Pves.max and Pves.thr were observed.Results:The trend of VV, VI, BC and △C was upwards on days 1, 3, and 5 postcystostomy.Meanwhile, compared with control group [VV: (1.408±0.033) mL, BC: (1.411±0.032) mL], VV and BC on day 1 and 3 postcystostomy were less[VV: (0.288±0.059) mL, (0.598±0.154) mL; BC: (0.292±0.059) mL, (0.601±0.154) mL]. There were statistically significant differences ( P<0.05). However, VV, PVR and BC on day 5 postcystostomy were not different from that of control group(all P>0.05). HE staining demonstrated that the HIS of days 1 and 3 postcystostomy and day 1 post-sham operation were in severe inflammatory phase, with HIS >4 scores.Additionally, the inflammation on day 5 in cystostomy group and days 3-5 in sham operation group were mild (HIS<2 scores). The correlation test of BC and HIS was negative( r=-0.880, P<0.001). After the application of anisodamine on dose of 0.2 mg/kg, VI, VV and BC of the young rats on day 3 postcystostomy significantly increased, compared with those before intervention [(643.500±65.889) s, (1.073±0.110) mL, (1.076±0.110) mL vs.(367.938±77.697) s, (0.612±0.129) mL, (0.617±0.129) mL, all P<0.05], while PVR, Pves.max and Pves.thr did not significantly change compared with those before intervention. Conclusion:The recent abnormal changes of urodynamics postcystostomy were related to the traumatic acute bladder inflammation in the young rats.On day 5 after the surgery, the bladder function basically returned to normal with the regression of the acute bladder inflammation.Anisodamine at 0.2 mg/kg dose could effectively relieve the symptoms of overactive bladder postcystostomy.