Investigations into the Presence of Functional 1 , 2 and 3-Adrenoceptors in Urothelium and Detrusor of Human Bladder

Purpose: We investigated the presence of functional 1, 2 and 3-adrenoceptor in urothelium and detrusor muscle of Materials and Methods: Expression of these adrenoceptors in surgically separated human urothelium and detrusor muscle produced by Results: 1, 2 and 3-adrenoceptor in both human urothelium and -adrenoceptors such as procaterol and isoproterenol evoked potent concentration-dependent relaxation of isolated human bladder strips with pD2 Conclusions: site of actions for the


INTRODUCTION
common form of pharmacologic treatment therapy mechanistic side effects related to effect of these evoked bladder contraction and alternative approach may be to develop drugs acting on the storage phase the muscarinic receptor antagonists act during the that bladder relaxation mediated by -adrenoceptors will be a viable target, because increased relaxation of the detrusor smooth muscle will lengthen the duration of storage phase in micturition cycle and thereby evoked by -adrenoceptor agonists is mainly mediated by 3-adrenoceptor agonist are said to stimulate the G protein nophosphate and causes relaxation of smooth muscle -adrenoreceptor induced relaxation of bladder are der are represented by 3-adrenoceptor agonists have been shown as compared with 1 and 2-adrenoceptor agonists, , and this was observed in normal and neurogenic blad-this was observed in normal and neurogenic blad-3-adrenoceptor agonists are expected to be -adrenoceptors in human bladder has been previously reported using receptor-binding studies, but the anatomical of -adrenoceptor are expressed in the urothelium has are expressed in the urothelium has Expression of of -adrenoceptors in urothelium is favored by the mounting evidence in support of a important role played by bladder epithelial cells in modulating bladder activity in response to local chemical and mechanical stimuli n this study, we aimed to investigate the we aimed to investigate the to investigate the presence of 1-, 2-and 3-adrenoceptor in separate tissue of urothelium and detrusor muscle from human 3-adrenoceptors , a selective a selective 3-adrenoceptor agonist

MATERIALS AND METHODS
Human bladders -The human bladders were informed consent from the next of kin of the six organ donors using an honest broker system from the Health disease status of organ donors was not available to ventitia was removed and longitudinal detrusor strips sutures were tied to each end of the strips, and tissues were lowered into the myobath multi-channel tissue a single PCR product of expected urothelium and detrusor was demonstrated by lack of any smooth muscle tissue stain in H&E staining lack of contamination from detrusor by lack of immunoreactivity for nonvascular smooth nonvascular smooth desmin in urothelium (data was tested by relaxation of human bladder strips by drugs were expressed as a percentage of the 10 -3 papaverine induced relaxation of tension produced

Figure 1 -
Figure 1 -Expression ß-adrenoceptors in human urothelium and adrenoceptors in human urothelium and s in human urothelium and detrusor.The representative ethidium bromide stained agarose gel of RT-PCR products for 1, 2 and 3-adrenoceptors show their mRNA expression in separated detrusor and urothelium tissue from 4 bladder specimens marked 1-4 on top.Lane from urothelium tissue of each bladder specimen is marked by U and lane for detrusor tissue is marked by D. Left lane is 100 bp DNA ladder in all gels and products of expected size are shown by bands for 1, 2 and 3-adrenoceptors in gels from top to bottom.Right most lane representative control with no template.

Figure 2 -
Figure 2 -H & E staining of surgically separated tissue of detrusor (Panel A) and urothelium (Panel B).Absence of any smooth muscle cells in urothelium section verify lack of contamination from detrusor in the expression studies demonstrated inFigure-1.

Figure 3 -
Figure 3 -Concentration dependent relaxation of the KCl-induced tone of human detrusor strips by Solabegron, Procaterol and Isoproterenol.Relaxation evoked by drugs in muscle strips pre-contracted with 30nM KCl is expressed as percentage of the relaxation

Figure 4 -
Figure 4 -A representative trace for the response of a human detrusor strip to EFS (5, 10, 15 Hz) in the presence of oxygenated Krebs' solution, and after 20 min incubation in Solabegron and Isoproterenol (10Isoproterenol (10 (10 -8 -10 -4 M).Both the drugs suppressed EFS evoked detrusor contraction at 10 -4 M concentration.The maximum suppression was observed at EFS induced contractions of lower frequencies as 5 Hz.