title: A quantitative analysis of purinoceptor expression in the bladders of patients with symptomatic outlet obstruction Electrical characteristics of suburothelial cells isolated from the human bladder. Suburothelial myofibroblasts in the human overactive bladder and the effect of botulinum neurotoxin type A treatment. Parallel changes in bladder suburothelial vanilloid receptor TRPV1 and pan‐neuronal marker PGP9.5 immunoreactivity in patients with neurogenic detrusor overactivity after intravesical resiniferatoxin treatment
abstract: Objective To compare the expression of the seven known P2X receptors in human bladder from male patients with detrusor instability caused by symptomatic bladder outlet obstruction with that from control bladders , using a quantitative reverse transcription‐polymerase chain reaction ( RT‐PCR ) method PURPOSE We measured the membrane electrical characteristics as well as the response to adenosine triphosphate of cells isolated from the suburothelial layer of the bladder . MATERIAL S AND METHODS Suburothelial cells were isolated from biopsy sample s of human bladder by collagenase disruption .  Electrophysiological measurements were done under current and voltage clamp to record membrane potential and ionic currents using patch pipettes with a K+ based filling solution . Intracellular [ Ca2 + ] was measured with Fura-2 . RESULTS Cells were different from epithelial cells by their spindle-shaped appearance with projections at either end . The cells stained for vimentin but epithelial and smooth muscle cells did not . The cells had small membrane capacitance ( 27 + /- 16 pF ) and a specific membrane resistance of 90 + /- 48 x 10(9 ) Omega cm2 . Average membrane potential was -63 + /- 14 mV but cells showed spontaneous spikes or r and om fluctuations of membrane potential . A small net inward current was superimposed by a larger outward current . Inward current was attenuated by the removal of extracellular Ca . Outward current showed large spontaneous fluctuations and was greatly decreased by 30 mM tetraethyl ammonium chloride . Adenosine triphosphate ( 30 to 100 microM ) elicited an inward current of about 50 pA and large intracellular Ca2 + transients . CONCLUSIONS These cells are electrically active which , in conjunction with the previous observation of connexin 43 labeling , suggests that they could act as an electrical network . A quantitative model of voltage distribution in such a network after the generation of inward current suggests that individual cells could not act as pacemakers , but rather a group of simultaneously activated cells could exert a peripheral excitatory effect that would amplify the magnitude of the original response . The implication s of this in terms of bladder sensation are discussed BACKGROUND An increasing body of evidence suggests a possible role of suburothelial myofibroblasts ( MFs ) in bladder mechanosensation and in the pathophysiology of detrusor overactivity ( DO ) . OBJECTIVE To determine whether markers of MFs , including gap junction protein connexin43 ( Cx43 ) and c-kit have altered immunohistochemical expression in the suburothelium of patients with neurogenic DO ( NDO ) or idiopathic DO ( IDO ) and whether this is affected by successful treatment of DO with botulinum neurotoxin type A ( BoNTA ) . DESIGN , SETTING , AND PARTICIPANTS Patients with NDO ( n=10 ) or IDO ( n=11 ) were treated in a single-centre , open-label study of intradetrusor BoNTA injections . Control tissue was obtained from 10 patients undergoing pelvic-floor repair procedures who had no overactive bladder ( OAB ) symptoms . This study is registered with Clinical Trials.gov , number NCT00662064 . INTERVENTIONS Bladder biopsies performed with flexible cystoscopes were obtained from control subjects and from NDO and IDO patients before BoNTA treatment and at 4 wk and 16 wk after treatment . They were studied with quantitative immunofluorescence using antibodies to connexin 43 ( Cx43 ) , vimentin , and c-kit . MEASUREMENTS Differences in Cx43 , vimentin , and c-kit immunoreactivity between control subjects and NDO or IDO patients ( primary outcomes ) . Changes in NDO or IDO , Cx43 immunoreactivity , and c-kit immunoreactivity after BoNTA treatment ( secondary outcomes ) . RESULTS AND LIMITATIONS Cx43 immunoreactivity was increased in both IDO and NDO patients compared to controls , but remained unchanged after BoNTA treatment . C-kit immunoreactivity was similar in NDO/IDO patients and controls and remained unchanged after BoNTA treatment . CONCLUSIONS Increased gap junction formation in the suburothelium has been demonstrated in biopsies from humans with DO . It is hypothesised that this change could have a significant role in the pathogenesis of the detrusor abnormality . Successful treatment of NDO or IDO does not appear to be associated with changes in the expression of Cx43 or c-kit on suburothelial MFs To compare PGP9.5 and transient receptor potential vanilloid receptor ( TRPV1 ) suburothelial immunoreactivity between controls and patients with spinal neurogenic detrusor overactivity ( NDO ) before and after treatment with intravesical resiniferatoxin , as suburothelial PGP9.5‐staining nerve fibres decrease in patients with spinal NDO who respond to intravesical capsaicin , and TRPV1 is present on these suburothelial nerve fibres in normal and overactive human urinary bladder
target: Studies revealed both structural and functional alterations in bladders from patients with LUTS symptoms or animals with experimentally induced bladder dysfunction .
  In particular , the urothelium and the suburothelial space , containing afferent nerve fibres and interstitial cells , have been found to form a functional unit that is essential in the process of bladder function .
  Various imbalances within this suburothelial complex have been identified as significant contributors to the generation of storage LUTS , along with potential abnormalities of central function
background: CONTEXT The focus of clinical underst and ing and management of male storage lower urinary tract symptoms ( LUTS ) has shifted from the prostate to the bladder .
  This is mirrored by an increasing body of experimental evidence suggesting that the bladder is the central organ in the pathogenesis of LUTS .
  OBJECTIVE A systematic review of the literature available on pathophysiologic aspects of storage LUTS .