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Renal pelvic and ureteral distension occurs in physiologic (diuresis) and pathologic (calculus) conditions. Its effect on the vesical and posterior urethral pressures as well as on the electromyographic (EMG) activity of the striated urethral sphincter (SUS) was investigated. The renal pelvis of 10 healthy volunteers (7␣men, 3 women; mean age 35.8 ± 8.6 years) was distended by means of a 4-F balloon-tipped catheter in␣increments of 2 ml of saline up to 10 ml and the response of the vesical and posterior urethral pressures and SUS EMG activity was recorded. The test was repeated with ureteral distension in increments of 0.25 ml up to 1 ml. The response of the aforementioned parameters was also registered after anesthetization of the renal pelvis, ureter and SUS. Two rates of renal pelvic and ureteral distension were tested: rapid (1 ml/s) and slow (1 ml/min). Renal pelvic distension with large volumes effected an increase of the renal pelvic and urethral pressures (P < 0.05, P < 0.05, respectively), a vesical pressure drop (P < 0.05) and increased EMG activity of the SUS. Ureteral distension caused a rise of ureteral and urethral pressures as well as of SUS EMG activity. With rapid distension, the aforementioned parameters responded at smaller volumes than with slow distension. Renal pelvic, ureteral or SUS anesthetization effected no urethral or SUS EMG response. It is suggested that the reaction of above parameters to distension indicates a mechanism regulating the urine flow so as to protect the renal pelvis and the ureter from being overloaded. The vesical pressure drop with increased SUS EMG activity on renal pelvis distension postulates a reflex relationship that we call the “reno-vesico-sphincteric reflex”. The role of this reflex in urine transport requires further study.

The exact role of the ileocecal valve (ICV) at the junction of small and large bowel is not well understood. Bowel segments used for the construction of urinary reservoirs incorporate the ICV. In the Indiana pouch its natural continence is used as one principle for achieving continence of the efferent limb. Motor activity and pressure in the ICV, the ileum and colon were registered in eight dogs. Myogenic activity of the bowel consisted of slow waves, irregular spontaneous contractions and superimposed spikes. Pressures of 7.2 +/- 0.3 cmH2O were recorded in the ileum and of 5.6 +/- 0.4 cmH2O in the colon. The pressure in the ICV was 12.7 +/- 0.4 cmH2O rising to 26.4 +/- 2.2 cmH2O during spontaneous depolarization. Balloon dilatation of the ileum resulted in relaxation of the ICV in 76% of experiments, whereas colonic distension was followed by a pressure increase in the ICV region in 80% of experiments. In 16% of cases a relaxation of the ICV area and a weaker response after repeated dilatation was noted. These findings make the ICV an unreliable continence mechanism as its long-term continence can not be predicted despite intraoperative evaluation. Additional measures to ensure consistent continence at the ICV (e.g. electric stimulation) need to be studied.

The effect of short-term urinary bladder distension on its cholinergic innervation was studied in Sprague-Dawley rats. Distension was induced for 3 h by forced diuresis and balloon outlet obstruction, and whole thick biopsy specimens were taken from the dome and lateral side of the anterior body 2, 7 and 21 days afterwards. The acetylcholinesterase (AChE) method was used to demonstrate the cholinergic nerves in the distended bladder wall. Cholinergic hypoinnervation was observed 7 days after the distension, persisting up to 21 days, although AChE-reactive nerves were then observed to be more numerous. The distribution of hypoinnervation was uneven, being more marked in the lateral side of the anterior body than in the dome. The distribution of AChE-reactive nerves varied even in the same biopsies, with areas of total hypoinnervation occurring next to areas of slightly diminished innervation. This was especially true 21 days after distension. The findings indicate transient damage to the cholinergic innervation, which may in turn explain the prolonged voiding difficulties often seen after catheterization of an overdistended bladder in a patient with urinary retention. The short-lasting effect of bladder dilatation therapy used to treat detrusor instability or interstitial cystitis may be due to the fairly rapid regeneration of cholinergic innervation.

With no consistent animal prototype for the study of varicocele, we set out to create a model in the rat by complete ligation of the main branch of left spermatic vein (MBSV) or by partial ligation of the left renal vein. Three months later, the histology, ultrastructure and temperature of the testis and epididymis were studied. Microscopically, spermatogenic arrest was the most frequent anomaly seen. The most frequently noted ultrastructural change of the testis was distension of smooth endoplasmic reticula in Sertoli cells. The microvilli of columnar epithelia in epididymis were sparse and showed local defects. Lesions and increased temperatures in the testis and epididymis induced by the ligation of the left MBSV were similar to those seen in partial ligation of the left renal veins, with no significant differences between left and right. Significant differences were found, however, on comparison with the controls.

WOS: 000227736400008 PubMed: 15619124 Neuropeptide Y (NPY) is known to be associated with the adrenergic system. The relationship among the late micturition disorders following acute urinary distension, the adrenergic system and NPY was investigated. A total of 90 rats were included in the study of which 30 acted as the control group. Acute urinary distension was created in 60 rats. The NPY concentration within their bladders was assessed by the use of radioimmunoassay (RIA) at 3 h after distension and subsequently on days 2, 7 and 21, then the third and sixth months. The NPY concentrations assessed in the third and sixth months were compared with the control group in the same age group. By means of the RIA method, a substantial decline of NPY concentration was observed at 2 days after distension, while the concentration started to increase after day 7 (P=0.003). This increase continued until the twenty first day (P=0.004). However, a significant decline was maintained when compared to the concentration before distension. In the third and sixth months, a significant decline were observed in the NPY concentration in comparison to the control group (P=0.004 and P=0.005, respectively). Early and late micturition disorders experienced after acute urinary distension may be the result of adrenergic denervation which may be related to NPY.

The urethral response to a sudden forced dilation was studied in ten healthy male volunteers aged from 27 to 71 years. Measurements were performed from the bladder neck and beyond the region of high pressure using a specially designed probe. The pressure response after dilation showed a characteristic course, which could be described by a double exponential function of the form: P(t) = P(equ) + P(alpha)e(-t/tau(alpha) + P(beta)e(-t/tau(beta) where P(t) is pressure at time t, P(equ) is equilibrium pressure after dilation, P(alpha) and P(beta) are pressure decay, and tau(alpha) and tau(beta) are time constants. The size and velocity of dilation, as well as the degree of distension before dilation, proved of significance for the magnitude of the pressure response. The characteristics of the pressure response are given by the properties of the periluminal structures strained during dilation, and are thus predominantly determined of elastic, collagen, muscular, and glandular components. However, a high degree of relaxation after straining, and a modest stiffness, indicates that the muscular component dominates the response. The significance of the prostatic tissues remains unclear.

We studied rabbit isolated erectile tissue responses to changes in preload and to active tension development with norepinephrine. The effects of antagonists of endothelin-1, prostaglandins E2 and F2alpha and of nitric oxide were also tested on normal and de-endothelialized preparations. Tissue distension was found to elicit spontaneous rhythmic contractions. Increase in preload diminished the latency of the spontaneous activity and augmented the developed force. Active tension development and the inhibitor of the Na+,K+ pump, ouabain, opposed the spontaneous activity. A marked reduction in the resting tension with abolition of the spontaneous activity was observed on normal, but not on de-endothelialized tissues, following the addition of the specific prostaglandin E2 and F2alpha receptor antagonist, SC-19220. At 3 x 10(-4) M, the highest concentration used, the endothelin-A receptor antagonist BQ-123 failed to change the pattern of the spontaneous activity and the resting tension of normal tissues. The nitric oxide synthesis inhibitor, L-NAME, did not produce reliable effects. These findings point to a causal relation between cavernosal tissue distension and phasic and tonic contractions. Phasic contractions appear to be elicited by smooth muscle cells through the enzyme Na+,K+-ATPase. Increase in the resting tone could be mediated, at least in part, by the endothelium, through the release of prostaglandins E2 and/or F2alpha but not of endothelins. We discuss the hypothesis that, in cavernosal tissue, mechanotransduction of distension to contractile responses is an important determinant of detumescence.

The purpose of this study was to investigate the response of the ureterovesical junction (UVJ) to ureteric distension and to bladder filling with the aim of elucidating the mechanism of UVJ antireflux. The study was performed on 13 healthy volunteers [age 41.4 +/- 10.2 (SD) years; nine men, four women]. A ureteric catheter connected to a pressure transducer was introduced into the ureter proper. After recording the ureteric pressure, the catheter was withdrawn to the bladder, and the resting pressures in the UVJ and bladder were registered. The catheter was positioned in the UVJ and a 3F balloon-tipped ureteric catheter was introduced into the ureter proper and filled saline in increments of 1 ml. The pressure response of the ureter and UVJ to ureteric distension was recorded. The bladder was then filled with 400 ml saline at two rates, slow (10 ml/min) and rapid (150 ml/min), and UVJ pressure response was registered. The aforementioned tests were repeated after anesthetizing the UVJ, the bladder musculature surrounding the UVJ and the ureteric wall at the site of the ureteric distension, respectively. Ureteric distension of the lower 2-3 cm effected ureteric pressure elevation (P < 0.05) and a UVJ pressure drop (P < 0.05); no pressure response of the UVJ occurred upon ureteric distension above this level. Slow bladder filling induced an increase in the UVJ (P < 0.01) and vesical (P < 0.01) pressures only when vesical filling reached a mean of 219.6 +/- 79.4 ml and above. Upon rapid vesical filling the pressure response occurred at a smaller volume (136.6 +/- 52.3 ml). The pressure response did not occur when the UVJ was anesthetized. The study showed that lower ureteric distension was associated with a UVJ pressure drop. This reflex relationship, which we call the "ureterovesical junction inhibitory reflex," was reproducible and disappeared on anesthetizing the UVJ or ureter. Vesical filling above a certain volume induced a UVJ pressure increase which was reproducible and disappeared on anesthetizing the UVJ; we call this reflex relationship the "vesicoureteral junction excitatory reflex." These two reflexes seem to regulate the entry of urine from the ureters to the bladder and prevent ureteric reflux during bladder filling. In conclusion, two reflexes are identified that might contribute to the mechanism of UVJ antireflux.

Urethral pressure was investigated by a method which allowed simultaneous measurement of the cross-sectional area. In healthy women a pressure range of 25-140 cm H2O was recorded at one urethral site as a response to the circumstances under which the measurement was performed. The pressures obtained were related to the degree of urethral distension and to the time after the change in distension. Measuring urethral pressure at one specific degree of distension results in one specific pressure value according to the dimensions of the measuring probe. However, this specific pressure value cannot be considered to supply more information on urethral sphincter function than any other pressures included in a range which can be obtained by changing the circumstances under which the measurement are carried out. More provocative methods of pressure measurement which simulate some of the physiological conditions of the urethra may provide more information on sphincter efficiency.

Uretersigmoidostomy in the adult has progressively been abandoned because of its high complication rate (both metabolic and functional). We have studied the feasibility of a new model of ureterorectal diversion in 12 Beagle dogs, with the aim of increasing rectal capacity and decreasing rectal pressure. A segment of the ileum was isolated and opened along its antimesenteric border to obtain a patch into which the right ureter was implanted, the left ureter being left intact to allow comparison of the kidneys postoperatively. The patch was then sutured to the edges of a large anterior rectotomy. Modifications of rectal physiology were studied by recording the rectal pressure after distension by a latex balloon both preoperatively and 3 months postoperatively, so that it was possible to evaluate the elasticity of the rectal wall. Radiographic studies and examination of autopsy specimens after 3 months yielded the impression of a reservoir added to the rectal space. Intrarectal pressure was significantly decreased (50% of the preoperative value) for a given distension volume following rectal augmentation (P

The effect of acute distension on vasoactive polypeptide (VIP)-, neuropeptide Y (NPY)- and substance P (SP)-immunoreactive nerves in the wall of the urinary bladder was investigated. At the age of 3 months, 25 female albino rats underwent forced diuresis combined with balloon obstruction to achieve maximal distension for 3 h. A modified, indirect immunofluorescence detection method was applied 2 days, 7 days and 21 days after distension. A marked, extensive depletion of VIP, NPY- and SP-immunoreactive nerves was observed after distension. This disturbance was reversible, and increased fluorescence of VIP-, NPY- and SP-immunoreactive nerve fibres compared with control specimens was seen in bladder specimens taken even as soon as 21 days after distension. This transient depletion of peptidergic innervation may partly explain the prolonged voiding problems that often occur after acute urinary retention. The depletion of sensory nerves containing SP shortly after distension may explain the transient benefit obtained from distension therapy in patients with painful bladder disease. It is suggested that the increased SP activity during the recovery phase may be related to neurogenic inflammation.

Urinary bladder blood flow as measured by the washout of locally injected 133Xe and by the simultaneously performed radioactive microsphere reference-sample method was studied in pigs. The washout curves were analyzed according to the initial slope, the corrected initial slope and the total curve. The corrected-initial-slope flow rates were not statistically significantly different from the microsphere whole-wall flow rates. The variability between the methods shown by the test-retest difference revealed only a minor lack of agreement. The bladder blood flow tended to decrease after the intravesical pressure had been increased to 20 cmH2O, but the difference was not statistically significant. Washout of locally injected 133Xe can be used for the evaluation of urinary bladder blood flow in humans and in longitudinal animal studies. The corrected-initial-slope method is recommended for the analysis of washout curves.

The blood flow of the dog urinary bladder measured by radioactive microsphere technique was compared to the clearance of locally injected 99mTechnetium pertechnate (99mTc) in the bladder wall. In semilogarithmic plots the 99mTc washout curves showed a multiexponential course. From the initial slopes (median 5.7 min) the bladder blood flow was calculated to be only 30-62% of the results obtained from the radioactive microsphere technique (blood flow in the muscular layer 21.7-44.8 ml/100 g/min). These lower values imply that the rate of removal of the hydrophilic tracer 99mTc at these flow rates is limited by the capillary diffusion capacity. The multiexponential curves reflect recirculation and excretion of 99mTc by the kidneys with accumulation of 99mTc in the bladder. It is concluded, that clearance studies of locally injected 99mTc in the bladder wall are unable to evaluate bladder blood flow.

The effect of distension on adrenergic innervation was investigated in the rat urinary bladder. Bladders were distended for 3 h by forced diuresis and balloon obstruction, and specimens were taken from the bladder dome, body and neck for the demonstration of glyoxylic acid-induced fluorescence of catecholamines. Depletion of catecholamines started after 10 h and was almost complete after 2 days. The fluorescence had recovered part way after 5-7 days and was practically normal after 21 days. Small, intensely fluorescent (SIF) cells in the ganglia continued to leak catecholamines throughout the 21-day study period. The primary clinical success of distension therapy for the treatment of unstable bladder may be at least partly due to a reversible disturbance in the function of the adrenergic nerves, which have an excitatory alpha-adrenergic dominance in such cases, but the persistent leakage from SIF cells raises the question of whether distension causes prolonged disturbances in bladder function.

Distension of the human urinary bladder often causes prolonged impairment of its function. To investigate the effects of the duration of stretch on bladder smooth muscle the active length-tension relation, electrically evoked, was described in rat detrusor strips during a short-term and a long-term stretch. The amplitude of active tension increased at first and then decreased abruptly at greater stretch lengths, the maximum being at muscle lengths 230-250% (100% = resting length) in both types of stretches. When the strips had been at maximum length (300%) for three hours the amplitude was significantly decreased during release as compared to the amplitude found during stretch to the maximum length at comparable lengths. If the strips were released immediately from the maximum length the amplitude responded in an opposite manner. Therefore we conclude that the duration of stretching of bladder smooth muscle significantly affects its mechanical activity.

Isolated sheep and human ureteral preparations (from patients with bilharzia) were subjected in-vitro to graded elongation and the effect on tension and spontaneous peristaltic frequency was assessed. Sheep specimens were obtained from three locations: the intra- and extrarenal portion of the pelvis and distal ureter. Elongation (stretch) induced an increase in spontaneous frequency only in pelvic ureteric specimens, but not in the distal ureter. Basal tension increased exponentially with stretch and most markedly in the distal sheep ureter and also in human preparations. Active tension (amplitude of phasic contractions) increased with stretch in specimens from all locations and reached a maximum at 110-115% elongation. These data suggest that acute distension of the ureter increases frequency of peristaltic waves only in the intrarenal parts of the ureter. Acute obstruction in renal colic can induce hypermotility in terms of increased frequency and force of contraction.

A probe for measurement of related values of cross sectional area (c.a.) and pressure in the resting female urethra has been developed. C.a. can be measured in the range 0.07 to 0.79 cm2 by means of the field gradient principle. Pressure is measured in the range 0 to 150 cm H2O. Pressure needed for inflation and deflation of the balloon ranges from +4 to -5 cm H2O with a hysteresis of 3 to 4 cm H2O. The probe is able to follow changes of the c.a. up to 0.7 cm2/sec. The method makes possible estimation of urethral stiffness/rigidity during distension of the balloon, estimation of the capability of contraction of the closure apparatus in terms of isometric and isotonic contraction, muscular work and power. Furthermore, hysteresis during inflation and deflation of the balloon can be described.