The ureterovesical innervation. A new concept based on a histochemical study

Diabetes Mellitus Promotes Smooth Muscle Cell Proliferation in Mouse Ureteral Tissue through the P-ERK/P-JNK/VEGF/PKC Signaling Pathway

Background and objectives: The aim of our study was to evaluate the role of diabetes mellitus (DM) as a significant factor affecting spontaneous stone expulsion, as suggested by previous research. Materials and methods: We investigated the influence of DM on the ureter using a murine model. The mouse-model arm of this study used 20 15 -week-old mice, including 10 normal (control) mice and 10 DM mice. We measured the proximal, middle and distal ureteral smooth muscle thickness in each mouse and the differences among ureteral sections were analyzed. Mouse ureteral specimens were also analyzed via western blotting to detect relative protein expression of phosphor–extracellular signal regulated kinases (P–ERK), phosphor–C–Jun N–terminal kinase (P–JNK), vascular endothelial growth factor (VEGF), and protein kinase C (PKC), which are representative factors involved in cell regulation. Results: We observed significant hyperproliferation of ureteral smooth muscle in DM mice compared to normal mice, which may provoke reduced peristalsis. The ureteral smooth muscle of DM mice was significantly thicker than that of normal mice in all ureteral tissues: proximal (p = 0.040), mid (p = 0.010), and distal (p = 0.028). The relative protein expression of P-ERK (p = 0.005) and P–JNK (p = 0.001) was higher in the diabetic group compared to the normal group. Additionally, protein expression of VEGF (p = 0.002) and PKC (p = 0.001) were remarkably up-regulated in DM mice. Conclusions: Hyperproliferation of ureteral smooth muscle was observed in DM mice, but not in normal mice. The pathways mediated by P–ERK, P–JNK, VEGF, and PKC may play an important role in pathological ureteral conditions.

Analysis of factors affecting spontaneous expulsion of ureteral stones that may predict unfavorable outcomes during watchful waiting periods: What is the influence of diabetes mellitus on the ureter?

Purpose

The aim of our study was to evaluate the association of several factors with spontaneous stone expulsion, including ureteral stone characteristics (size, location, hydronephrosis, perinephric stranding), types of medications prescribed (α-blocker, low-dose steroid), and other possible demographic and health-history factors (gender, age, serum creatinine, underlying diabetes mellitus [DM], and hypertension).

Materials and Methods

A total of 366 patients with ureteral stones were enrolled. All patients underwent watchful waiting without any invasive procedures. Initial diagnoses of ureteral stones were confirmed by computed tomography scans, which were taken at approximately 1-month intervals to check for stone expulsion. Univariate and multivariate analyses were conducted to identify significant factors that contributed to stone expulsion.

Results

Among 366 patients, 335 patients (91.5%) experienced spontaneous stone passage during a mean follow-up period of 2.95±2.62 weeks. The patients were divided into two groups depending on the success of spontaneous stone passage. Univariate analyses revealed that stone location (p=0.003), stone size (p=0.021), and underlying DM (p<0.001) were significant predictors of stone passage. Multivariate analyses confirmed that stone size (p=0.010), stone location (p=0.008), and underlying DM (p=0.003) were independent predictive factors affecting stone passage.

Conclusions

Stone size, location, and underlying DM were confirmed to be significant predictive factors for spontaneous passage of ureteral stones. Urologists should consider active procedures, such as shock wave lithotripsy or ureteroscopy, rather than conservative management in patients presenting with proximally located stones, large ureteral stones, or underlying DM.

The effect of smoking on spontaneous passage of distal ureteral stones

Background

Animal studies have shown that nicotine affects the peristalsis of the ureter. The aim of the study is to analyze the effect of smoking on spontaneous passage of distal ureteral stones.

Methods

88 patients in whom distal ureteral stone below 10 mm diameter diagnosed with helical computerized tomography enhanced images were reviewed. Patients were grouped as either smokers (n:33) or non smokers (n:50). Follow-up for spontaneous passage of stones was limited with 4 weeks. Patients did not receive any additional medical treatment other than non-steroid anti inflamatory drugs only during painful renal colic episodes.

Two groups were compared with the chi-square test in terms of passing the stone or not. Stone passage was confirmed with either the patient collecting the stone during urination or by helical CT.

Results

Smoking habits was present in 30(34%) patients and the frequency in both groups were similar (smokers: 23(76%) vs non-smokers: 46(79%)). Spontaneous passage of the stone was observed in 69(78%) patients. The two groups were comparable in terms of patien age, male to female ratio and stone size. Stone passage decreased as stone diameter increased. Total stone passage rates were similar in both groups (smokers: 76% vs. non-smokers: 79%) (p > 0.05). Passage of stones > 4 mm was observed in 46% and 67% of smokers and non-smokers respectively. However passage of stones with a diameter ≤ 4 mm were similar in both groups (smokers: 100% vs non-smokers: 92%) (p > 0.05).

Conclusion

Smoking has neither a favorable nor un-favorable effect on spontaneous passage of distal ureteral stones. However, spontaneous passage rates in patients with a stone diameter > 4 mm was lower in smokers. These results should be further confirmed with studies including larger numbers of patients.

Identification of c-kit-positive cells in the mouse ureter: the interstitial cells of Cajal of the urinary tract

The existence of a pacemaker system in the urinary tract capable of orchestrating the movement of filtrated urine from the ureteral pelvis to the distal ureter and lower urinary tract seems intuitive. The coordinated activity necessary for such movement or "peristalsis" would likely require an intricate network of cells with pacemaker-like activity, as is the case with the interstitial cells of Cajal (ICC) of the gut. We investigated whether these putative pacemaker cells of the urinary tract are antigenically similar to ICC of the gut by using immunofluorescence staining for c-kit, a cell-surface marker specific for ICC. Ureteral, urinary bladder, and urethral tissues were harvested from female mice of the WBB6F1 strain, and fixed sections were prepared and stained for c-kit. Cell networks composed of stellate-appearing, c-kit-positive, ICC-like cells were found in the lamina propria and at the interface of the inner longitudinal and outer circular muscle layers of the ureteral pelvis but not in the urinary bladder or urethra. Thus, like in the gut, c-kit-positive, ICC-like cells are present in the urinary tract but appear to be restricted to the proximal ureter of this murine species.

The structure and autonomic innervation of the vesico-ureteric junction in cases of primary ureteric reflux

OBJECTIVE

To determine the histological structure and autonomic innervation of the vesico-ureteric junction (VUJ) in cases of primary ureteric reflux, to compare the results with those reported previously for non-refluxing VUJs and thus determine possible structural anomalies which could be responsible for vesico-ureteric reflux (VUR).

MATERIALS AND METHODS

Nineteen specimens of VUJs with reflux were obtained from four males and 10 females undergoing ureteric reimplantation. Serial frozen sections were cut and stained either with Masson's trichrome or immunostained for protein gene product (PGP 9.5), a general nerve marker, dopamine beta hydroxylase (D beta H), a marker for noradrenergic nerves, or neuropeptide Y (NPY).

RESULTS

Longitudinally orientated muscle bundles of narrow diameter accompanied the ureter to its termination at the ureteric orifice. Where they merged with those of the superficial trigone. In some specimens, an additional muscle component was identified, situated on the outer aspect of the ureteric muscle coat, consisting of an incomplete layer of distinctive muscle whose constituent cells formed an interlacing mesh-work. Occasionally, specimens included detrusor muscle which consisted of relatively large diameter compact bundles separated from the ureter by a connective tissue sheath. D beta H- and NPY-immunoreactive (-IR) nerves were numerous among the ureteric muscle bundles. Many NPY-IR nerves occurred within the detrusor muscle while D beta H-IR nerves were mainly perivascular. When present, the outer muscle component was richly innervated by both D beta H- and NPY-IR nerves. PGP immunoreactivity varied among regions in the same section, PGP-IR nerves frequently being less numerous than those containing D beta H or NPY.

CONCLUSION

These results indicate that the morphology of the VUJ in cases of VUR is indistinguishable from the normal VUJ described previously. Furthermore, the density and distribution of D beta H- and NPY-IR nerves is identical to that in controls. However, the antigenicity of PGP in the reflux specimens appears to be masked in some regions by an unknown factor.

A double-label immunohistochemical study of intramural ganglia from the human male urinary bladder neck

Double-label immunocytochemistry was used to investigate the colocalisation of various neuropeptides and the enzymes nitric oxide synthase (NOS) and tyrosine hydroxylase (TH) in intramural ganglia of the human male urinary bladder neck and trigone. Postmortem specimens were obtained from 7 male infants and children ranging in age from 2 mo to 3 y who had died as a result of cot death or accidental trauma. On average 60% of the intramural neurons were non-TH-immunoreactive (-IR) (i.e. presumptive cholinergic) and 40% were TH- and D beta H-IR (i.e. noradrenergic). Within the non-TH-IR population, calcitonin gene-related peptide (CGRP) was found in 65% of cells, neuropeptide Y (NPY) in 90%, nitric oxide synthase (NOS) in 45%, somatostatin (SOM) in 90%, and vasoactive intestinal polypeptide (VIP) in 40%. The corresponding values for the TH-IR neurons were CGRP (54%), NPY (70%), NOS (58%), SOM (73%) and VIP (40%). All the observed bombesin (BOM)-immunoreactivity was colocalised with TH while 90% of VIP and almost all the CGRP was colocalised with NPY. Less than 5% of neurons were immunoreactive for substance P (SP) or met-enkephalin (m-ENK) and some of these also contained TH. Varicose nerve fibres were seen in close proximity to some of the intramural neurons, the majority of such varicosities showing immunoreactivity to CGRP, VIP or TH. Less common were pericellular varicosities immunoreactive to NPY, SOM or SP. These results demonstrate the neurochemical heterogeneity of intramural neurons in the human bladder neck and provide indirect evidence for the complexity of the peripheral innervation of the human urinary bladder.

Urinary bladder function and drug development

Disorders of the bladder are extremely common and are becoming more so in an ageing population. Recently, our understanding of lower urinary tract physiology and pathology has also increased. Here, Douglas Ferguson and Nim Christopher summarize this new knowledge of lower urinary tract function, the changes in innervation that occur with age and the common disease states, and discuss how it is being used to develop new drug treatments for bladder disorders.

Nitroxergic innervation of the human ureterovesical junction

Nitric oxide synthase (NOS) immunohistochemistry and nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry were used to investigate the distribution of nitroxergic, i.e., nitric oxide-synthesizing, neuronal perikarya and processes in the human ureterovesical junction (UVJ). Tissue specimens obtained from two cadaver kidney donors and two patients undergoing radical cystectomy for bladder cancer were examined. Clusters of NOS-immunoreactive neurons were localized in extramural ureterovesical ganglia. NOS-containing nerve fibers traveled within large extramural nerve trunks and marched among smooth muscle bundles. Extramural and intramural blood vessels were encircled by varicose NOS-positive axonal processes. The distribution of NOS immunoreactivity paralleled the staining pattern for NADPH-d activity. Urothelium stained strongly for NADPH-d activity but showed no NOS immunolabeling. Specimens from all four patients investigated showed similar staining patterns. Our results suggest that nitric oxide, a potent smooth-muscle-relaxing neurotransmitter in the autonomic nervous system, plays a physiologic role in opening the human UVJ.

Dopamine D1 and D2 receptors in the human ureter and urinary bladder: a radioligand binding and autoradiographic study

OBJECTIVE

To analyse the pharmacological profile and the anatomical localization of the dopamine D1 and D2 receptors in sections of the pelvic part of the ureter and of the fundus of the urinary bladder.

PATIENTS, MATERIALS AND METHODS

Samples of the pelvic part of the ureter and of the fundus of the urinary bladder were taken in men (age range 61 +/- 4 years) who were undergoing lower urinary tract surgery. Biochemical characterization and autoradiographical techniques were used on frozen sections of the ureter or the urinary bladder. [3H]-SCH 23390 was used as a ligand of dopamine D1 receptors and [3H]-spiroperidol as a ligand of dopamine D2 receptors.

RESULTS

[3H]-SCH 23390 and [3H]-spiroperidol were bound by specific sections of the ureter and of the urinary bladder. The pharmacological profile of the binding was consistent with the labelling of D1 and D2 receptors respectively. Light microscope analysis of the localization of D1 and D2 receptors revealed the accumulation of the two radioligands in the tunica muscularis of the ureter or of the urinary bladder.

CONCLUSION

A possible role of the dopaminergic system in the control of urine flow and of some dysfunctions of the lower urinary tract is suggested.

An immunohistochemical study of the innervation of the ureterovesical junction in infancy and childhood

OBJECTIVE

To use histological and immunohistochemical methods to study the structure and innervation of the human ureterovesical junction (UVJ).

MATERIALS AND METHODS

A series of 24 post-natal specimens taken from patients ranging in age from 1 month to 6 years were examined. Routine histological slides were stained with Masson's trichrome. In addition, an indirect immunohistochemical method was used to study the occurrence and distribution of nerves immunoreactive for the neuropeptides vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), substance P (SP) and calcitonin gene-related peptide (CGRP). Immunoreactivity to tyrosine hydroxylase (TH), dopamine-B-hydroxylase (DBH) and to protein gene product (PGP) 9.5, a general nerve marker, were also studied.

RESULTS

The UVJ comprised a ureteric muscle component (the intramural ureter) and a detrusor component (the immediately adjacent region of the urinary bladder). In the majority of specimens a third or intermediate layer was also present. This additional component consisted of tightly-packed smooth muscle cells which formed an incomplete layer that partially surrounded the juxta-vesical and intramural parts of the ureter. Numerous PGP-, VIP-, NPY, DBH- and TH- like immunoreactive (-LIR) nerves were associated with the smooth muscle bundles which comprised the intramural ureter. Such nerves ran in the connective tissue separating ureteric smooth muscle bundles and rarely coursed amongst individual smooth muscle cell comprising each bundle. SP- and CGRP- containing nerves were rarely observed in association with the intramural ureter and none were detected in the ureteric submucosa. The intermediate muscle layer was richly innervated by PGP-, TH-, DBH- and NPY- containing nerves which ran amongst the smooth muscle cells comprising this layer. VIP-, SP- and CGRP-LIR nerves were not observed within the intermediate layer. The detrusor component of the UVJ was innervated by PGP-, NPY- and VIP-LIR nerves which frequently extended between the smooth muscle cells forming the detrusor muscle bundles. TH-, DBH-, SP- and CGRP-LIR nerve fibres were rarely encountered.

CONCLUSION

These findings indicate that noradrenergic nerves play a major role in the control of the ureteric component of the UVJ. In addition, the present results form baseline morphological data with which to compare the results of future studies on the structure of the UVJ in cases of vesicoureteric reflux.

Immunohistochemical demonstration of nerves and nerve cells in human and porcine ureters

There are divergent opinions about the origin of ureteral motility. It is either a myogenic or a neutral phenomenon. Furthermore, the existence of nerve cells in the ureter is also a controversial question. In the present study we applied immunohistochemical methods to human and porcine ureters in an attempt to clarify the mattern. As neuronal markers we used anti-PGP 9.5 and anti-NSE, and as a glial marker anti-S-100. In the whole mount preparations of pig ureter we observed two neuronal plexuses on both sides of the tunica muscularis. The inner plexus consisted of both nerve bundles and nerve cells, whereas the outer one did not contain any nerve cells. In the human ureter we found a ganglion with nerve cells beneath the tunica muscularis and the tunica adventitia.

Mechanisms implicated in the histamine response of the sheep ureterovesical junction

The isotonic response of the sheep ureterovesical junction to histamine receptor agonists and antagonists was studied in vitro. Histamine (10(-7)-10(-4) M) produced a concentration-dependent contraction which was dependent on the extracellular calcium concentrations. Nifedipine (10(-9)-10(-6) M) partially inhibited the contractile response to histamine. 2-Methylhistamine and 2-pyridylethylamine elicited contractile effect in a concentration-related manner. The order of potency was histamine greater than 2-methylhistamine greater than 2-pyridylethylamine. Dimaprit and 4-methylhistamine produced no response in this tissue. The histamine contraction was antagonized by mepyramine, the pA2 value being 8.41, but not by cimetidine (10(-4) M). Scopolamine (10(-5) M) and indomethacin (10(-6) M) had an inhibitory effect. Phentolamine (10(-5) M), propranolol (10(-7)) and hexamethonium (10(-6) M) did not alter the histamine-induced contractions. The present results indicate that the response to histamine in sheep ureterovesical junction is mediated mainly by a direct action on the smooth muscle through excitatory histamine H1-receptors and partly by an indirect action via the stimulation of intramural cholinergic nerves.

Paraganglial cells of urinary bladder and prostate: potential diagnostic problem

A transurethral prostatic resection for prostatism in a 73 year old man showed a cluster of richly capillarised clear cells originally thought to be indicative of invasive carcinoma. Immunohistochemical studies were carried out on this tissue specimen and three similar cases using a variety of antibodies--Neuron specific enolase, PGP 9.5, chromogranin, synaptophysin, serotonin, somatostatin, substance P, calcitonin, calcitonin gene related peptide, met-enkephalin, VIP, neurofilament, CAM 5.2, S100 protein, prostatic specific antigen and prostatic acid phosphatase. The cellular foci were shown to be composed of paraganglionic cells. The cell clusters were well defined and predominantly comprised clear cells with scanty, fine eosinophilic cytoplasmic granules in three cases. The cell nuclei were round to oval, moderately pleomorphic, with evenly dispersed dense chromatin. It is concluded that the presence of minute foci of paraganglial cells in the bladder wall and prostate gland may be misinterpreted as malignant because of their close association with nerves and their relative rarity. Immunohistochemical staining with neuroendocrine markers should dispel any doubt about their identity.

An in vitro pharmacological study of the human trigone--a site of non-adrenergic, non-cholinergic neurotransmission

Muscle strips from the human detrusor and trigone were studied in vitro. The detrusor muscle contracted strongly to both cholinergic receptor stimulation with carbachol and to electrical field stimulation. There was no evidence of atropine resistance in the detrusor strips. The superficial trigone responded maximally to alpha-adrenergic receptor stimulation but also produced a significant cholinergic response. Intramural nerve stimulation in the presence of both atropine and phentolamine produced a residual non-adrenergic, non-cholinergic (NANC) response of 40% of its maximum at 5 Hz. Electrical stimulation, particularly at the lower frequencies of stimulation, produced relaxation responses in 40% of the superficial trigonal muscle strips. These relaxations were not blocked by atropine, phentolamine or propranolol, but were abolished by tetrodotoxin. The possible role of the cholinergic "input" to the superficial trigone and the importance of the NANC excitatory and inhibitory innervation in preventing vesico-ureteric reflux and and in aiding bladder neck opening is discussed.

Detrusor inhibition in suprasacral spinal cord injuries: is it due to sympathetic overactivity?

The authors report five patients with detrusor inactivity in suprasacral spinal cord lesions with perineal spasticity. In all of these cases with cervical or high thoracic lesions treatment with an alpha-blocking drug (Phenoxybenzamine) allowed bladder activity to return. These results suggest that the sacral parasympathetic centre is under the inhibitory influence of the sympathetic nervous system.

Peptide-containing nerves in human urinary bladder

Nerves containing immunoreactive vasoactive intestinal polypeptide (VIP), substance P and two newly discovered peptides, neuropeptide tyrosine (NPY) and PHI (peptide having N-terminal histidine and C-terminal isoleucine), have been found in the human urinary bladder by immunocytochemistry and radioimmunoassay. Somatostatin immunoreactivity was detected by radioimmunoassay. The VIP-immunoreactive nerves were widely distributed in all regions, but were particularly dense beneath the epithelium and in the muscle layer. Scattered intramural ganglia were found to be reactive to VIP antiserum. Higher concentrations of extractable VIP were detected in the trigone than in the dome. VIP- and PHI-immunoreactive nerves were similarly distributed, the latter being less numerous. NPY-immunoreactive nerves were seen mainly in the muscle layer, particularly in the trigonal area. The distribution patterns of VIP- and NPY-immunoreactive nerves resembled those of the previously reported cholinergic and adrenergic nerves, respectively. Many blood vessels were found to be innervated by both types of immunoreactive nerves. Scattered substance P-immunoreactive fibers were occasionally seen, being present in the submucosa and around the detrusor muscles. The significance of these nerves remains to be elucidated.

Intramural ganglia of the human urinary bladder

The arrangement and distribution of intramural autonomic ganglion cells have been examined in samples of the dome and lateral walls of the human urinary bladder. Ganglia were frequently observed in samples removed from either site and possessed histochemical characteristics to support their classification as presumptive cholinergic neurons. Unlike pelvic autonomic neurons, intramural bladder ganglion cells are not associated with noradrenergic (possibly inhibitory) preganglionic nerve terminals. The widespread distribution of ganglion cells within the bladder wall serves to frustrate surgical attempts to denervate detrusor smooth muscle. The outcome of such operative procedures is likely to result in decentralisation rather than denervation of the urinary bladder.

A morphometric study of the pelvi-ureteric junction and review of the pathogenesis of upper ureteric obstruction

A morphometric analysis has been made of the normal human pelvi-ureteric junction and upper ureter. There was found to be no anatomically definable pelvi-ureteric junction. Muscle bundles of renal pelvis and upper ureter run a spiral course and do not form clear-cut layers. There is a great normal variation of thickness of the renal pelvic and ureteric muscularis, as well as of the total thickness of these structures. Smaller, but sometimes still large differences, are seen between right and left pelvi-ureteric specimens of individual patients. Suggested normal ranges of thickness are: (1) Renal pelvis: total thickness 340-1300 micrometers, muscularis 270-1100 micrometer. (2) Upper ureter: total thickness 450-1000 micrometer, muscularis 240-790 micrometer. No neurones are present in the renal pelvis or upper ureter. The possible etiologies of pelvi-ureteric obstruction are discussed.

Study of ureteral reflux in neurogenic dysfunction of the bladder: the concept of a neurogenic ureter and the role of the periureteral sheath in the genesis of reflux and supersensitive response to autonomic drugs

Ureteral pressure and its response to autonomic stimulations were investigated in paraplegics with ureteral reflux and compared to the response in patients with primary reflux, paraplegics without reflux, normal individuals and a patient who had undergone lumbar sympathectomy. Only the paraplegics with ureteral reflux responded supersensitively to the administration of an alpha-adrenergic drug. The demonstration of the specificity of this response to the lower end of the ureter suggested that although it is caused by the changes in the bladder it is dependent on the connection between the bladder and the distal ureter through the periureteral sheath. The ureteral ends in paraplegics with reflux that respond supersensitively to autonomic stimulations were proposed as possibly true cases of a neurogenic ureter in that it is believed to be a consequence of concomitant injury to the ipsilateral parasympathetic motor neuron to the periureteral sheath at the sacral spinal cord level. In the discussion on the mechanism of denervation supersensitivity reference is made to the modern concept of dual neuroanatomy of the ureteral sheath.

Denervation supersensitivity of the urethra to alpha-adrenergics in the chronic neurogenic bladder

The response of the urethral pressure profile to the administration of various autonomic drugs was compared between a group of eight patients with chronic neurogenic bladder as evidenced by denervation supersensitivity to besacholineR and a group of 10 control subjects. A supersensitive response to the administration of an alpha-stimulant with a rise of maximum urethral pressure of 10 mmHg or more above the control urethral pressure was uniformly observed in the urethra of patients with chronically denervated bladders. Mechanisms of supersensitivity are postulated and the significance of alpha-adrenergic innervation of the urethra are stressed. These results appear to add pharmacological evidence of alpha-adrenergic predominance in the urethra which is now believed to be dually innervated.

Ureteral structure and ultrastructure. Part I. The normal human ureter

Twenty-eight normal human ureters were examined under the light and electron microscope. Three uretero-trigonal units were microdissected. The ureter is a non-layered muscular tube wherein the anatomical unit is muscle bundles that contain heterogeneously oriented muscle cells. Functional continuity of muscle cells is provided through the nexus, which are clearly defined structures. A group of morphologically distinct muscle cells are identified and these may represent the ureteral pacemaker cells. The functional status of muscle cells causes certain morphologic changes and, thus, the cells fixed in contraction differ from those fixed in relaxation and in vitro testing of muscle cell contractility is feasible. The ultrastructure of the normal urothelium and the adrenergic and cholinergic components of ureteral nerves are presented briefly.

Disorders of micturition: neuropharmacologic basis and results of drug therapy

The clinical use of various pharmacologic agents in problems of micturition is based on the new concepts of intrinsic urethrovesical innervation, presence and regional predominance of autonomic neuroreceptors, and experimental evidence of the effects of various drugs on the bladder and the urethra. A new concept, relating to the processes that control bladder filling and emptying, is coming into being and replacing the traditional concept based on anatomic grounds alone. On the basis of the published data, and from personal experience both experimental and clinical, pharmacologic agents singly or in combination can be effectively and safely used in various problems of micturition such as incontinence (enuresis, stress incontinence in women, postprostatectomy, urgency incontinence), and functional outflow obstruction caused by neurologic or non-neurologic disease processes.

Innervation of the muscle of the bladder in the rat

A quantitative ultrastructural analysis of the organisation and terminal density of the nerves associated with the muscle of the body of the bladder was undertaken in the rat. The results obtained were suggestive of the organisation of the intramuscular plexuses into 2 separate and possibly functionally distinct networks. The nerves ramifying within the muscle fascicles mostly contained between 1 and 3 axons and on the basis of counts made in 12 animals, appeared to provide the muscle with only a moderate level of innervation. Although adrenergic terminals were frequently seen in the perivascular plexuses, they were rarely encountered in the nerves within the muscle fascicles. The majority of the terminals in the intrafascicular nerves were similar to those normally classified as cholinergic and, in many, the exposed parts of the axonal membrane were closely related to that of adjacent muscle cells. In addition to clear vesicles and large dense-cored vesicles, many of these terminals contained scattered small dense-cored vesicles. It was suggested that the involvement of the material present in the small dense-cored vesicles with acetylcholine in impulse transmission might account for the atypical features of such transmission in the bladder and in particular its resistance to blockade by atropine. The nerves forming the interfascicular networks contained few axons with cholinergic terminals, and were characterised by much larger numbers of a morphologically distinctive type of terminal. Some of these were indistinguishable from those recently defined as the terminals of purinergic axons but their distribution in the nerves suggests that they represent the terminals of afferent axons and is consistent with the concept that, together with those observed in other tissues, such axons are involved in pain perception.

Effect of long-term chemical sympathectomy on function of canine urinary tract

Destruction of the adrenergic terminals in the ureter, bladder, and urethra was produced and maintained in 4 dogs for periods up to twelve months by biweekly intraperitoneal injections of 6-hydroxydopamine. The effects on urine transport, storage, and elimination were studied. The results are discussed in the light of current knowledge regarding the sympathetic innervation of these organs and its function.

Ultrastructural evidence for adrenergic and cholinergic innervation of the human ureter

Electron microscopic study of the autonomic innervation of the human ureter demonstrated the existence of adrenergic and cholinergic nerve terminals. The 2 types of nerves were observed in the adventitia, smooth muscle layer and submucosa. The presence of adrenergic and cholinergic nerves was confirmed with the aid of 5-hydroxydopamine, a false sympathetic neurotransmitter that may be used as a specific marker for adrenergic nerve endings at the ultrastructural level. Adrenergic and cholinergic nerves were observed to run in close contact with each other in the same nerve fiber, providing ultramorphological evidence for a possible interaction between the 2 components of the autonomic nervous system in the human ureter.

Cholinergic and adrenergic neuroreceptors in urinary tract of female dogs. Evaluation of function with pharmacodynamics

Our preliminary pharmacodynamic studies on the lower urinary tract of adult female dogs indicate that cholinergic and adrenergic (alpha and beta) neuroreceptors in the urethra appear to coordinate the detrusor and urethral function during micturition. Urethral resistance measured as urethral pressure was easily altered with various pharmacologic agents. However, only bethanechol elicited detrusor response measured as intravesical pressure. The possible clinical usefulness of various drugs is outlined. Our results indicate the therapeutic value of ephedrine sulfate and propranolol in stress urinary incontinence; phenoxybenzamine in neurogenic vesical dysfunction and functional outlet obstruction; phenoxybenzamine plus bethanechol in atonic neurogenic bladder; and imipramine in enuresis.