Role of glycine in nociceptive and non-nociceptive bladder reflexes and pudendal afferent inhibition of these reflexes in cats.

AIM: This study examined the role of glycinergic transmission in nociceptive and non-nociceptive bladder reflexes and in inhibition of these reflexes by pudendal nerve stimulation (PNS). METHODS: Cystometrograms (CMGs) were performed in α-chloralose anesthetized cats by intravesical infusion of saline or 0.25% acetic acid (AA) to trigger, respectively, non-nociceptive or nociceptive bladder reflexes. PNS at 2 or 4 times threshold (T) intensity for inducing anal twitch was used to inhibit the bladder reflexes. Strychnine (a glycine receptor antagonist) was administered in cumulative doses (0.001-0.3 mg/kg, i.v.) at 60-120 min intervals. RESULTS: Strychnine at 0.001-0.3 mg/kg significantly (P < 0.05) increased bladder capacity and reduced contraction amplitude during saline CMGs but did not change these parameters during AA CMGs except at the 0.3 mg/kg dose which increased bladder capacity. Strychnine did not alter PNS inhibition during saline CMGs except at the highest dose at 2T intensity, but significantly (P < 0.05) suppressed PNS inhibition during AA CMGs after 0.001-0.003 mg/kg doses at 2T and 4T intensities. During AA CMGs strychnine (0.3 mg/kg) also unmasked a post-PNS excitatory effect that significantly reduced bladder capacity after termination of PNS. CONCLUSIONS: Glycinergic inhibitory neurotransmission in the central nervous system plays an unexpected role to tonically enhance the magnitude and reduce the bladder volume threshold for triggering the non-nociceptive bladder reflex. This is attributable to inhibition by glycine of another inhibitory mechanism. Glycine also has a minor role in PNS inhibition of the nociceptive bladder reflex. Neurourol. Urodynam. 35:798-804, 2016. © 2015 Wiley Periodicals, Inc.

Inflammatory myofibroblastic tumor of the bladder masquerading as eosinophilic cystitis: case report and review of the literature.

A 9-year-old boy presented with gross hematuria of 2 days duration. Cystoscopic evaluation revealed an anterior bladder mass. Pathology was consistent with eosinophilic cystitis, and a steroid regimen was initiated accordingly, but no improvement ensued. Concern for alternate malignant pathology led to open resection and the ultimate diagnosis of inflammatory myofibroblastic tumor of the bladder. Inflammatory myofibroblastic tumor is a rare tumor of the bladder in children and to our knowledge has not previously been associated with a misleading eosinophil-rich mucosal inflammatory response.

Role of spinal metabotropic glutamate receptor 5 in pudendal inhibition of the nociceptive bladder reflex in cats.

This study examined the role of spinal metabotropic glutamate receptor 5 (mGluR5) in the nociceptive C-fiber afferent-mediated spinal bladder reflex and in the inhibtion of this reflex by pudendal nerve stimulation (PNS). In α-chloralose-anesthetized cats after spinal cord transection at the T9/T10 level, intravesical infusion of 0.25% acetic acid irritated the bladder, activated nociceptive C-fiber afferents, and induced spinal reflex bladder contractions of low amplitude (<50 cmH2O) and short duration (<20 s) at a smaller bladder capacity ∼80% of saline control capacity. PNS significantly (P < 0.01) increased bladder capacity from 85.5 ± 10.1 to 137.3 ± 14.1 or 148.2 ± 11.2% at 2T or 4T stimulation, respectively, where T is the threshold intensity for PNS to induce anal twitch. MTEP {3-[(2-methyl-4-thiazolyl)ethynyl]pyridine; 3 mg/kg iv, a selective mGluR5 antagonist} completely removed the PNS inhibition and significantly (P < 0.05) increased bladder capacity from 71.8 ± 9.9 to 94.0 ± 13.9% of saline control, but it did not change the bladder contraction amplitude. After propranolol (3 mg/kg iv, a ß1/ß2-adrenergic receptor antagonist) treatment, PNS inhibition remained but MTEP significantly (P < 0.05) reduced the bladder contraction amplitude from 18.6 ± 2.1 to 6.6 ± 1.2 cmH2O and eliminated PNS inhibition. At the end of experiments, hexamethonium (10 mg/kg iv, a ganglionic blocker) significantly (P < 0.05) reduced the bladder contraction amplitude from 20.9 ± 3.2 to 8.1 ± 1.5 cmH2O on average demonstrating that spinal reflexes were responsible for a major component of the contractions. This study shows that spinal mGluR5 plays an important role in the nociceptive C-fiber afferent-mediated spinal bladder reflex and in pudendal inhibition of this spinal reflex.

Timing and predictors for urinary drainage in children with expectantly managed grade IV renal trauma.

PURPOSE: We determined which children sustaining blunt grade IV renal trauma are at greatest risk for failing nonoperative management and in what time frame they will likely present. MATERIALS AND METHODS: We retrospectively reviewed children presenting with nonvascular grade IV blunt renal trauma between 2003 and 2012. We compared characteristics on computerized tomography, reasons for intervention, type and timing of surgery, length of hospital stay and need for readmission between children undergoing early intervention (less than 72 hours after admission) and those managed conservatively (with any subsequent intervention undertaken more than 72 hours after admission). RESULTS: A total of 26 children were identified with nonvascular grade IV blunt renal trauma. Conservative management was attempted in 16 cases (62%). Seven of these patients (44%) required intervention (ureteral stent and/or percutaneous drain placement), with a mean time to intervention of 11 days. Collecting system clot and larger urinoma (1.45 cm in cases with successful and 4.29 cm in those with failed conservative management) significantly predicted failure of conservative management (p<0.05). Presence of dissociated renal fragments (57% vs 11%) and interpolar contrast extravasation (57% vs 0%) were increased in the early intervention group compared to the conservatively managed group (p>0.05), as was rehospitalization (43% vs 0%), mean length of stay (7.9 vs 5.4 days) and transfusion (14% vs 0%, p>0.05). CONCLUSIONS: Collecting system hematoma and urinoma size significantly predicted failure of conservative management, with a mean time to intervention of 11 days. Children with failed conservative management had a greater incidence of dissociated renal fragments and interpolar extravasation. Early identification of these patients may decrease hospital readmissions, length of stay and prolonged morbidity.