The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Robert M. Levin - One of the best experts on this subject based on the ideXlab platform.
-
Grapes and Urinary Bladder Function
Grapes and Health, 2016Co-Authors: Robert M. Levin, Robert E Leggett, Catherine SchulerAbstract:The Function of the Urinary Bladder is to collect and store urine at low intravesical pressure and then, periodically, to expel the urine via a highly coordinated and sustained contraction. Bladder Function depends on several factors including state of innervation, vascularization, structure of the organ as a whole, contractile response of the smooth muscle (SM) elements to autonomic stimulation, availability of metabolic energy (cytosolic adenosine triphosphate [ATP] and mitochondrial oxidative metabolites), and the density and distribution of the connective tissue in the detrusor. These factors are intimately connected, and an alteration in one factor can induce substantial adaptive changes in the others.
-
effect of letrozole on Urinary Bladder Function in the female rabbit
BJUI, 2007Co-Authors: Alexandra Rehfuss, Catherine Whitbeck, Paul Chichester, Yungshun Juan, Anita Mannikarottu, Robert M. LevinAbstract:OBJECTIVE To investigate the effect of letrozole (a potent aromatase inhibitor that effectively inhibit the synthesis of oestrogen) on Bladder contraction with changes in morphology and biochemistry. MATERIALS AND METHODS Sixteen female New Zealand white rabbits were separated into four equal groups; groups 1–3 were given oral letrozole for 1, 2 and 3 weeks, and group 4 was given saline and served as the control group. At the end of the medication period each rabbit was anaesthetized and the Bladder muscle strips were used for contractile, histological and biochemical studies. RESULTS The concentration of serum oestrogen was significantly lower and testosterone was significantly higher in letrozole-treated rabbits than in the control group. The rabbits treated for 1 week with letrozole showed significant decreases in the contractile responses to electrical field stimulation, ATP and carbachol, but not to KCl. Contractility returned to normal in the rabbits treated for 2 and 3 weeks. Letrozole resulted in an increased volume percentage of collagens and decreased Bladder compliance. The volume percentage of the smooth muscle component also changed, with a significant decrease at 1 week and then a gradual increase at 2 and 3 weeks. Contractile dysFunction was absent at 2 and 3 weeks, which was consistent with no change in sarcoplasmic reticulum Ca2+-ATPase content or mitochondrial Function. CONCLUSIONS The Bladder contractility decline in the first week and was restored at 2 and 3 weeks. The present study unexpectedly showed the possibility that testosterone might be as important as oestrogen in the contractile Function of the female Bladder.
-
role of nitric oxide in Urinary Bladder Function effect of l arginine
Urologia Internationalis, 2007Co-Authors: Catherine Whitbeck, Rebekah Sokol, Paul Chichester, Robert M. LevinAbstract:Background: Evidence indicates that decreased blood flow to the Bladder plays a major role in obstructive Bladder dysFunction in the rabbit model of partial Bladder outlet obstructi
-
Effect of ethanol on protection of Urinary Bladder Function by grape suspensions
Urology, 2005Co-Authors: Canan Aldirmaz Agartan, Catherine Whitbeck, Paul Chichester, Robert M. LevinAbstract:Abstract Objectives To compare the protective effects of grape suspensions prepared in an aqueous vehicle with grape suspensions prepared in an 8% ethanol vehicle in rabbits subjected to partial outlet obstruction. The hypothesis was that the presence of ethanol would increase the absorption of the beneficial components of the grape suspensions and thus increase their protective ability. The use of ethanol in these studies was not to simulate wine. Methods A total of 48 New Zealand white rabbits were separated into eight groups of 6 rabbits each. Groups 1 and 3 were pretreated by oral gavage for 3 weeks with grape suspensions in water; groups 2 and 4 were treated with vehicle. Groups 5 and 7 were treated with the grape suspensions in 8% ethanol, and groups 6 and 8 were treated with ethanol vehicle. Groups 1, 2, 5, and 6 underwent sham operations, and groups 3, 4, 7, and 8 underwent partial outlet obstruction. Three weeks after surgery, the rabbits were evaluated. Results The Bladder weight had significantly increased in all obstructed groups. The contractile responses to field stimulation and carbachol were reduced in all obstructed groups, although the responses in both grape-treated groups were greater than both vehicle-treated groups. The contractile responses to potassium chloride were significantly reduced by partial outlet obstruction in both obstructed groups similarly. Conclusions Both grape suspensions provided protection against obstructive-induced Bladder dysFunction. The ethanol preparation of the grape suspension was not better than the aqueous preparation.
-
protection of Urinary Bladder Function by grape suspension
Phytotherapy Research, 2004Co-Authors: Canan Aldirmaz Agartan, Catherine Whitbeck, Rebekah Sokol, Paul Chichester, Robert M. LevinAbstract:Urinary Bladder dysFunction secondary to BPH is a major affliction of aging men. A rabbit model of partial outlet obstruction was used to evaluate the ability of a standardized grape suspension to protect the Bladder against obstructive Bladder dysFunction. Twenty-four New Zealand White rabbits were separated into four groups of six rabbits each. Groups 1 and 3 were pretreated by oral gavage for 3 weeks with a standardized grape suspension suspended in water; groups 2 and 4 were treated with vehicle. Groups 1 and 3 received sham operations after 3 weeks of treatment; groups 2 and 4 received partial outlet obstruction by surgically placing a silk ligature loosely around the urethra. At 3 weeks following surgery, in vivo and in vitro Bladder Functions were evaluated. Based on both in vivo and in vitro studies, the grape suspension significantly reduced the severity of obstructed Bladder dysFunction. This is consistent with the hypothesis that ischemia is a major etiological factor in obstructive dysFunction, and treatment with antioxidants and membrane stabilization compounds such as those in the grape suspension can be effective in the treatment of obstructive Bladder pathology. Copyright © 2004 John Wiley & Sons, Ltd.
Penelope A. Longhurst - One of the best experts on this subject based on the ideXlab platform.
-
calcium regulation of Urinary Bladder Function
The Journal of Urology, 1997Co-Authors: Margot S Damaser, Penelope A. Longhurst, Alan J Wein, Robert M. LevinAbstract:ABSTRACTPurpose: To investigate the effect of independently inhibiting calcium influx from extracellular sources and calcium release from intracellular stores on the ability of the Urinary Bladder to generate pressure and empty.Materials and Methods: Rabbit Bladders were mounted in an in vitro whole organ bath and filled with 15 ml. saline. Each Bladder was incubated separately in Tyrode's solution, with diltiazem (10 micro M), to block extracellular calcium influx, or with thapsigargin (40 micro M) and ryanodine (80 micro M), to block the uptake and release of calcium from the sarcoplasmic reticulum. The Bladder was then stimulated isometrically with field stimulation (32 Hz), and to empty with field stimulation and with bethanechol (250 micro M), independently. During stimulation, transmural pressure and volume emptied were measured. From these, flow rate, power, and external mechanical work were calculated.Results: In the presence of diltiazem, the time to maximal pressure decreased while the rate of p...
-
Modulation of Urinary Bladder Function by Sex Hormones in Streptozotocin-Diabetic Rats
The Journal of Urology, 1994Co-Authors: Berit Eika, Robert M. Levin, Penelope A. LonghurstAbstract:AbstractThe modulation of Urinary Bladder Function by sex hormones was examined in castrated and sham-operated male and female streptozotocin-diabetic rats. Male and female diabetic rats weighed less than age-matched controls and had significantly greater serum glucose levels and Bladder weights. Castration had no effect on Bladder mass and did not alter the diabetes-induced changes in rat or Bladder mass. Protein concentrations were significantly increased and collagen concentrations were significantly decreased in Bladders from diabetic rats compared with nondiabetics. Sex or castration had no effects on protein or collagen concentration of Bladders from nondiabetic and diabetic rats. There were no differences in water consumption and urine excretion between male and female nondiabetic rats, and no effects of castration were observed on micturition in nondiabetic rats. Ovariectomy followed by diabetes caused a significant increase in urine excretion compared with diabetes alone. Ovariectomized diabetic ...
-
Rabbit as a model of Urinary Bladder Function
Neurourology and Urodynamics, 1994Co-Authors: Robert M. Levin, Penelope A. Longhurst, Frederick C. Monson, Alan J WeinAbstract:Micturition is a complex neuromuscular process. Although control mechanisms have been identified at several levels of the central nervous system and spinal cord, the final pathway in the control of micturition is the autonomic innervation of the Urinary Bladder and related structures. Following this line of reasoning further, micturition is ultimately dependent on the ability of the Urinary Bladder to both contract and generate intravesical pressure, and to modify its shape in such a way as to efficiently expel its contents without leaving a high residual volume. In order to understand the various elements of micturition, a wide variety of both in vivo and in vitro animal models has been developed. In many cases, animal models have been utilized to describe the effect of specific experimental pathologies on the lower Urinary tract. The current review of the use of the rabbit in urological research is not meant to be a comprehensive treatise on the topic, but should provide a rational description of the how this species can be utilized to study both normal and pathological Function. © 1994 Wiley-Liss, Inc.
-
comparison of Urinary Bladder Function in rats with hereditary diabetes insipidus streptozotocin induced diabetes mellitus and nondiabetic osmotic diuresis
The Journal of Urology, 1994Co-Authors: Penelope A. Longhurst, Robert M. Levin, Berit EikaAbstract:Abstract In vivo and in vitro Bladder Function were studied in three different models of increased diuresis: 1) Brattleboro rats with hereditary diabetes insipidus (di/di), 2) Sprague-Dawley rats with streptozotocin-induced diabetes mellitus (STZ), and 3) Sprague-Dawley rats with increased diuresis due to 5% sucrose added to the drinking water. When compared with controls, all three models showed Bladder mass, increased water consumption and urine output, higher mean and maximal increased micturition volumes, and greater Bladder capacity and compliance by in vitro cystometry. The changes were more extensive in di/di rats than in STZ and sucrose-drinking rats. The concentration of Bladder collagen decreased in all three rat models when compared with controls. However, the collagen concentration of STZ Bladders was significantly lower than the collagen concentration of di/di and sucrose Bladders, suggesting that the decrease in Bladder collagen concentration associated with experimental diabetes mellitus is only partly related to the increased diuresis. Contractile Function was studied using a whole Bladder model. Responses of whole Bladders from control and diabetic rats to electrical field stimulation, carbachol and KCl were identical. Volume-pressure relations of the isolated whole Bladder showed that the magnitude of the contractile response to KCl is constant at intravesical volumes ranging from about 10 to 95% of cystometrical Bladder capacity. Bladders from Brattleboro di/di rats and STZ rats showed a rightward shift of volume-passive pressure curves when compared with appropriate controls. Bladders from sucrose-drinking rats had volume-passive pressure curves similar to the Bladders from controls. This study suggests that while contractile Function remains intact with increased diuresis, the passive Function changes, with the Bladder becoming more distensible.
-
comparison of Urinary Bladder Function in 6 and 24 month male and female rats
The Journal of Urology, 1992Co-Authors: Penelope A. Longhurst, Berit Eika, Robert E Leggett, Robert M. LevinAbstract:Abstract Micturition characteristics, collagen composition, and in vitro Urinary Bladder strip contractility were examined in young adult (six month) and old (24 month) male and female Fischer 344 rats. Although young female rats consumed significantly less water than young males, there were no differences in volumes of urine excreted. Old females excreted significantly more urine than old males, but there were no differences in volumes of water consumed. Old male rats had similar micturition frequencies during the light and dark cycles, in contrast to females and young males, where the number of micturitions during the dark cycle was significantly greater than those during the light cycle. The mean and maximal micturition volumes were significantly greater in old males compared to young males and old females during both the light and dark cycles. Bladders from female rats weighed significantly less than Bladders from males of the same age, and the Bladders from young rats weighed less than those of old rats. The protein and collagen concentrations were significantly less in Bladder bodies from young females than old females. The amount of collagen resistant to digestion by Pronase, and thus thought to be cross-linked, was significantly greater in Bladders from old rats compared to young. No differences between groups were found in the contractile responses of Bladder base strips. There were trends for the absolute contractile responses of Bladder body strips from old males to field stimulation, carbachol, ATP, and KCl to be larger than the other groups, and for strips from the young females to be smaller. The responses of strips from young females to field stimulation and KCl were significantly less than those of young males or old females, and responses to 10~3 M ATP were less than those of old females. Responses of strips from old males to 60 mM KC1 were significantly greater than those of young males. The differences in contractility could be attributed to the differences in strip mass. It appears, therefore, that Urinary Bladder Function in male and female rats is unaffected by increasing age between 6 and 24 months.
Margaret A Vizzard - One of the best experts on this subject based on the ideXlab platform.
-
social stress induces changes in Urinary Bladder Function Bladder ngf content and generalized Bladder inflammation in mice
American Journal of Physiology-regulatory Integrative and Comparative Physiology, 2014Co-Authors: Abbey Peterson, Gerald C Mingin, Cuixia Shi Erickson, Mark Nelson, Margaret A VizzardAbstract:Social stress may play a role in Urinary Bladder dysFunction in humans, but the underlying mechanisms are unknown. In the present study, we explored changes in Bladder Function caused by social stress using mouse models of stress and increasing stress. In the stress paradigm, individual submissive FVB mice were exposed to C57BL/6 aggressor mice directly/indirectly for 1 h/day for 2 or 4 wk. Increased stress was induced by continuous, direct/indirect exposure of FVB mice to aggressor mice for 2 wk. Stressed FVB mice exhibited nonvoiding Bladder contractions and a decrease in both micturition interval (increased voiding frequency) and Bladder capacity compared with control animals. ELISAs demonstrated a significant increase in histamine protein expression with no change in nerve growth factor protein expression in the Urinary Bladder compared with controls. Unlike stressed mice, mice exposed to an increased stress paradigm exhibited increased Bladder capacities and intermicturition intervals (decreased voiding frequency). Both histamine and nerve growth factor protein expression were significantly increased with increased stress compared with control Bladders. The change in Bladder Function from increased voiding frequency to decreased voiding frequency with increased stress intensity suggests that changes in social stress-induced Urinary Bladder dysFunction are context and duration dependent. In addition, changes in the Bladder inflammatory milieu with social stress may be important contributors to changes in Urinary Bladder Function.
-
overexpression of ngf in mouse urothelium leads to neuronal hyperinnervation pelvic sensitivity and changes in Urinary Bladder Function
American Journal of Physiology-regulatory Integrative and Comparative Physiology, 2010Co-Authors: Birthe Schnegelsberg, Margaret A Vizzard, Gary Cain, Anindya Bhattacharya, Philip A Nunn, Anthony P D W Ford, Debra A CockayneAbstract:NGF has been suggested to play a role in Urinary Bladder dysFunction by mediating inflammation, as well as morphological and Functional changes, in sensory and sympathetic neurons innervating the Urinary Bladder. To further explore the role of NGF in Bladder sensory Function, we generated a transgenic mouse model of chronic NGF overexpression in the Bladder using the urothelium-specific uroplakin II (UPII) promoter. NGF mRNA and protein were expressed at higher levels in the Bladders of NGF-overexpressing (NGF-OE) transgenic mice compared with wild-type littermate controls from postnatal day 7 through 12–16 wk of age. Overexpression of NGF led to Urinary Bladder enlargement characterized by marked nerve fiber hyperplasia in the submucosa and detrusor smooth muscle and elevated numbers of tissue mast cells. There was a marked increase in the density of CGRP- and substance P-positive C-fiber sensory afferents, neurofilament 200-positive myelinated sensory afferents, and tyrosine hydroxylase-positive sympathetic nerve fibers in the suburothelial nerve plexus. CGRP-positive ganglia were also present in the Urinary Bladders of transgenic mice. Transgenic mice had reduced Urinary Bladder capacity and an increase in the number and amplitude of nonvoiding Bladder contractions under baseline conditions in conscious open-voiding cystometry. These changes in Urinary Bladder Function were further associated with an increased referred somatic pelvic hypersensitivity. Thus, chronic urothelial NGF overexpression in transgenic mice leads to neuronal proliferation, focal increases in Urinary Bladder mast cells, increased Urinary Bladder reflex activity, and pelvic hypersensitivity. NGF-overexpressing mice may, therefore, provide a useful transgenic model for exploring the role of NGF in Urinary Bladder dysFunction.
-
Urinary Bladder Function and somatic sensitivity in vasoactive intestinal polypeptide vip mice
Journal of Molecular Neuroscience, 2008Co-Authors: Simon Studeny, Bopaiah P Cheppudira, Susan Meyers, Elena M Balestreire, Gerard Apodaca, Lori A Birder, Karen M Braas, James A Waschek, Margaret A VizzardAbstract:Vasoactive intestinal polypeptide (VIP) is an immunomodulatory neuropeptide widely distributed in neural pathways that regulate micturition. VIP is also an endogenous anti-inflammatory agent that has been suggested for the development of therapies for inflammatory disorders. In the present study, we examined Urinary Bladder Function and hindpaw and pelvic sensitivity in VIP−/− and littermate wildtype (WT) controls. We demonstrated increased Bladder mass and fewer but larger urine spots on filter paper in VIP−/− mice. Using cystometry in conscious, unrestrained mice, VIP−/− mice exhibited increased void volumes and shorter intercontraction intervals with continuous intravesical infusion of saline. No differences in transepithelial resistance or water permeability were demonstrated between VIP−/− and WT mice; however, an increase in urea permeability was demonstrated in VIP−/− mice. With the induction of Bladder inflammation by acute administration of cyclophosphamide, an exaggerated or prolonged Bladder hyperreflexia and hindpaw and pelvic sensitivity were demonstrated in VIP−/− mice. The changes in Bladder hyperreflexia and somatic sensitivity in VIP−/− mice may reflect increased expression of neurotrophins and/or proinflammatory cytokines in the Urinary Bladder. Thus, these changes may further regulate the neural control of micturition.
-
Urinary Bladder Function and Somatic Sensitivity in Vasoactive Intestinal Polypeptide (VIP) −/− Mice
Journal of Molecular Neuroscience, 2008Co-Authors: Simon Studeny, Bopaiah P Cheppudira, Susan Meyers, Elena M Balestreire, Gerard Apodaca, Lori A Birder, Karen M Braas, James A Waschek, Margaret A VizzardAbstract:Vasoactive intestinal polypeptide (VIP) is an immunomodulatory neuropeptide widely distributed in neural pathways that regulate micturition. VIP is also an endogenous anti-inflammatory agent that has been suggested for the development of therapies for inflammatory disorders. In the present study, we examined Urinary Bladder Function and hindpaw and pelvic sensitivity in VIP−/− and littermate wildtype (WT) controls. We demonstrated increased Bladder mass and fewer but larger urine spots on filter paper in VIP−/− mice. Using cystometry in conscious, unrestrained mice, VIP−/− mice exhibited increased void volumes and shorter intercontraction intervals with continuous intravesical infusion of saline. No differences in transepithelial resistance or water permeability were demonstrated between VIP−/− and WT mice; however, an increase in urea permeability was demonstrated in VIP−/− mice. With the induction of Bladder inflammation by acute administration of cyclophosphamide, an exaggerated or prolonged Bladder hyperreflexia and hindpaw and pelvic sensitivity were demonstrated in VIP−/− mice. The changes in Bladder hyperreflexia and somatic sensitivity in VIP−/− mice may reflect increased expression of neurotrophins and/or proinflammatory cytokines in the Urinary Bladder. Thus, these changes may further regulate the neural control of micturition.
Alan J Wein - One of the best experts on this subject based on the ideXlab platform.
-
Estrogen modulates the expression of myosin heavy chain in detrusor smooth muscle.
American Journal of Physiology-cell Physiology, 2001Co-Authors: Ricardo Sanchez-ortiz, Alan J Wein, Ze Wang, Chandrakala Menon, Michael E. Disanto, Samuel ChackoAbstract:The effect of low serum estrogen levels on Urinary Bladder Function remains poorly understood. Using a rabbit model, we analyzed the effects of estrogen on the expression of the isoforms of myosin,...
-
calcium regulation of Urinary Bladder Function
The Journal of Urology, 1997Co-Authors: Margot S Damaser, Penelope A. Longhurst, Alan J Wein, Robert M. LevinAbstract:ABSTRACTPurpose: To investigate the effect of independently inhibiting calcium influx from extracellular sources and calcium release from intracellular stores on the ability of the Urinary Bladder to generate pressure and empty.Materials and Methods: Rabbit Bladders were mounted in an in vitro whole organ bath and filled with 15 ml. saline. Each Bladder was incubated separately in Tyrode's solution, with diltiazem (10 micro M), to block extracellular calcium influx, or with thapsigargin (40 micro M) and ryanodine (80 micro M), to block the uptake and release of calcium from the sarcoplasmic reticulum. The Bladder was then stimulated isometrically with field stimulation (32 Hz), and to empty with field stimulation and with bethanechol (250 micro M), independently. During stimulation, transmural pressure and volume emptied were measured. From these, flow rate, power, and external mechanical work were calculated.Results: In the presence of diltiazem, the time to maximal pressure decreased while the rate of p...
-
Fetal bovine Bladder: physiology and pharmacology.
Advances in Experimental Medicine and Biology, 1995Co-Authors: Edward J. Macarak, Alan J Wein, John W. Duckett, Howard M. Snyder, Robert M. LevinAbstract:The Function of the lower Urinary tract is to store urine at low intravesical pressure, and then to periodically expel the urine via a highly coordinated sustained contraction. To a large extent, Urinary Bladder Function is dependent on the state of the neuronal innervation, the structure of the organ as a whole and the contractile response of smooth muscle elements1,2.
-
Rabbit as a model of Urinary Bladder Function
Neurourology and Urodynamics, 1994Co-Authors: Robert M. Levin, Penelope A. Longhurst, Frederick C. Monson, Alan J WeinAbstract:Micturition is a complex neuromuscular process. Although control mechanisms have been identified at several levels of the central nervous system and spinal cord, the final pathway in the control of micturition is the autonomic innervation of the Urinary Bladder and related structures. Following this line of reasoning further, micturition is ultimately dependent on the ability of the Urinary Bladder to both contract and generate intravesical pressure, and to modify its shape in such a way as to efficiently expel its contents without leaving a high residual volume. In order to understand the various elements of micturition, a wide variety of both in vivo and in vitro animal models has been developed. In many cases, animal models have been utilized to describe the effect of specific experimental pathologies on the lower Urinary tract. The current review of the use of the rabbit in urological research is not meant to be a comprehensive treatise on the topic, but should provide a rational description of the how this species can be utilized to study both normal and pathological Function. © 1994 Wiley-Liss, Inc.
-
effects of sensitization on female guinea pig Urinary Bladder Function in vivo and in vitro studies
The Journal of Urology, 1991Co-Authors: Penelope A. Longhurst, Robert M. Levin, Alan J WeinAbstract:Abstract Although Bladder inflammation is known clinically to produce a variety of symptoms including urgency, frequency, and pain, there are only a few experimental studies that directly relate Bladder inflammation with urodynamic and Functional alterations. We have used the sensitized guinea pig model to study the effects of inflammation on micturition parameters, cystometry, and in vitro Bladder contractility. This model depends on the allergic response of the Bladder mucosa to ovalbumin, an otherwise non-irritative agent, as an antigen. In vivo exposure of the Bladder to ovalbumin via urethral catheterization induced a prompt and marked increase in the number of micturitions in antigen-sensitized guinea pigs. Ovalbumin had no effects on the micturition parameters in the control group. Using in vivo cystometry, intravesical exposure to ovalbumin induced a significant decrease in both the pressure at which micturition was induced, and the volume at which micturition was induced. Ovalbumin had no effect on cystometric parameters of the control animals. In vitro exposure of whole-Bladder preparations to ovalbumin induced a significant contractile response only in the Bladders isolated from the sensitized guinea pigs. The responses of the isolated Bladders to field stimulation and bethanechol were identical for Bladders from both sensitized and control animals. In conclusion, exposure of the Bladder to ovalbumin in the sensitized animal induced an increase in the frequency of micturitions and a decrease in the pressure and volume at which micturition was induced. Thus, intravesical exposure of the Bladder mucosa to a substance that the Bladder has been sensitized to can induce alterations in micturition that are consistent with the clinical symptoms of “urgency and frequency”.
Robert E Leggett - One of the best experts on this subject based on the ideXlab platform.
-
Grapes and Urinary Bladder Function
Grapes and Health, 2016Co-Authors: Robert M. Levin, Robert E Leggett, Catherine SchulerAbstract:The Function of the Urinary Bladder is to collect and store urine at low intravesical pressure and then, periodically, to expel the urine via a highly coordinated and sustained contraction. Bladder Function depends on several factors including state of innervation, vascularization, structure of the organ as a whole, contractile response of the smooth muscle (SM) elements to autonomic stimulation, availability of metabolic energy (cytosolic adenosine triphosphate [ATP] and mitochondrial oxidative metabolites), and the density and distribution of the connective tissue in the detrusor. These factors are intimately connected, and an alteration in one factor can induce substantial adaptive changes in the others.
-
the effect of 2 and 4 week ovariectomy on female rabbit Urinary Bladder Function
Urology, 2009Co-Authors: Yungshun Juan, Anita Mannikarottu, Suning Li, Tasmina Hydery, Barry A Kogan, Robert E LeggettAbstract:Objectives To evaluate the effect ovariectomy (OVX) after 2 and 4 weeks on Bladder Function and biochemistry of the adult female rabbit Urinary Bladder. Methods Twelve mature female rabbits were divided into 3 groups: control, 2-week ovariectomized, and 4-week ovariectomized. At the end of the experimental period, the following studies were performed: contractile studies on isolated strips; examinations of the activity of citrate synthase (a marker for mitochondrial Function) and thapsigargin-sensitive calcium ATPase (a marker for sarcoplasmic reticular calcium uptake Function); and quantification of Rho-kinase (ROK) α and β and myosin light chain kinase by Western blot analyses. Results By 28 days after OVX, there were significant decreases in Bladder weight, contractile responses, and citrate synthase and sarcoplasmic reticular calcium uptake activity. In addition, by 28 days following OVX the relative concentration of ROK α was significantly increased, whereas ROK β concentration was significantly decreased. Myosin light chain kinase was significantly reduced. Conclusions Our study demonstrated that OVX contributed significantly to chronically decreased contractile Function in the detrusor muscle of the female rabbit Bladder, and this decrease, in turn, was mediated by decreased mitochondrial and sarcoplasmic reticulum Function. These specific Bladder dysFunctions could be related to the demonstrated decreased blood flow to the Bladder muscle and mucosa and the increased generation of free radicals. Changes in smooth muscle regulatory proteins, especially myosin light chain kinase, may also play a role in contractile dysFunctions.
-
effect of doxazosin on rat Urinary Bladder Function after partial outlet obstruction
Neurourology and Urodynamics, 2002Co-Authors: Robert E Leggett, Catherine Whitbeck, George Eagen, Robert M. LevinAbstract:Hypoxia induced by partial outlet obstruction is believed to play a major role in both the hypertrophic and degenerative effects of partial outlet obstruction. Doxazosin (dox) is a clinically effective α-adrenergic antagonist used in the treatment of symptomatic benign prostatic hyperplasia (BPH). Although the major therapeutic effect of the agent is believed to occur on the smooth muscle components of the prostate by reducing prostatic urethral resistance and thus improving emptying, dox may have part of its clinical action via effects mediated by other actions, including via spinal α-adrenergic receptors or direct effects on the Bladder, possibly via inhibition of vascular alpha receptors. The specific aim of the current study was to determine whether dox pretreatment on rats affects blood flow to the Bladder and reduces the level of Bladder dysFunction induced by partial outlet obstruction. In part 1, eight rats were separated into two groups of four rats each. Group 1 received oral administration of dox (30 mg/kg) for 4 weeks; group 2 received vehicle (5% dimethyl sulfoxide). After 4 weeks of treatment, blood flow studies were performed using fluorescent microspheres and the Bladders excised, frozen, and submitted to Interactive Medical Technologies (IMT) for blood flow analysis. In part 2, 32 adult male rats were separated into four groups of eight rats each. Groups 1 and 2 received oral administration of dox (30 mg/kg) for 4 weeks, groups 3 and 4 received vehicle (5% dimethyl sulfoxide). At 4 weeks, the rats in groups 1 and 3 received partial outlet obstructions and treatment continued for an additional 2 weeks. After 6 weeks of treatment (total), each rat was anesthetized, the Bladder excised, weighed, and isolated strips mounted and contractility studies performed. 1) Four weeks pretreatment of rats with dox increased blood flow to the Bladder in both the control and obstructed groups. 2) Partial outlet obstruction induced a mild decrease in blood flow. 3) The magnitude of the increased Bladder weight in the vehicle-treated obstructed group was significantly greater than in the dox-treated obstructed group. 4) Partial outlet obstruction resulted in significant decreases in the contractile response to field stimulation in both treated and non-treated rats. The magnitude of the decreased response was significantly greater in the non-treated rats. 5) The response to potassium chloride was significantly reduced by partial outlet obstruction in the vehicle-treated group but not in the dox-treated group. 6) The time to maximal tension was significantly increased in response to carbachol, adenosine triphosphate, and potassium chloride. However, the magnitude of the increase was significantly greater for the vehicle-treated obstructed groups stimulated by potassium chloride than for the dox-treated groups. Dox treatment of rats increased blood flow to the Bladder and reduced the severity of the response to partial outlet obstruction. These beneficial effects would be due to pharmacological effects on α-adrenergic systems outside those present in the prostate. These include effects on blood flow to the Bladder, effects on the micturition centers of the central nervous system, spinal reflexes, and α-adrenergic receptors in the urethra and Bladder. Neurourol. Urodynam. 21:160–166, 2002. © 2002 Wiley-Liss, Inc.
-
comparison of Urinary Bladder Function in 6 and 24 month male and female rats
The Journal of Urology, 1992Co-Authors: Penelope A. Longhurst, Berit Eika, Robert E Leggett, Robert M. LevinAbstract:Abstract Micturition characteristics, collagen composition, and in vitro Urinary Bladder strip contractility were examined in young adult (six month) and old (24 month) male and female Fischer 344 rats. Although young female rats consumed significantly less water than young males, there were no differences in volumes of urine excreted. Old females excreted significantly more urine than old males, but there were no differences in volumes of water consumed. Old male rats had similar micturition frequencies during the light and dark cycles, in contrast to females and young males, where the number of micturitions during the dark cycle was significantly greater than those during the light cycle. The mean and maximal micturition volumes were significantly greater in old males compared to young males and old females during both the light and dark cycles. Bladders from female rats weighed significantly less than Bladders from males of the same age, and the Bladders from young rats weighed less than those of old rats. The protein and collagen concentrations were significantly less in Bladder bodies from young females than old females. The amount of collagen resistant to digestion by Pronase, and thus thought to be cross-linked, was significantly greater in Bladders from old rats compared to young. No differences between groups were found in the contractile responses of Bladder base strips. There were trends for the absolute contractile responses of Bladder body strips from old males to field stimulation, carbachol, ATP, and KCl to be larger than the other groups, and for strips from the young females to be smaller. The responses of strips from young females to field stimulation and KCl were significantly less than those of young males or old females, and responses to 10~3 M ATP were less than those of old females. Responses of strips from old males to 60 mM KC1 were significantly greater than those of young males. The differences in contractility could be attributed to the differences in strip mass. It appears, therefore, that Urinary Bladder Function in male and female rats is unaffected by increasing age between 6 and 24 months.
-
Urinary Bladder Function in the tight-skin mouse.
The Journal of Urology, 1992Co-Authors: Penelope A. Longhurst, Berit Eika, Robert E Leggett, Robert M. LevinAbstract:Abstract Tight-skin mice develop hypertrophy of connective tissue and tendons, associated with increases in collagen concentration in skin, heart, lungs, and tail. The Bladders from these mice have not previously been examined. Because of the purported importance of collagen in Bladder wall structure and compliance, we examined collagen content, micturition characteristics, and length-tension relationships in Bladders from tight-skin mice. Bladder collagen content and concentration were approximately 70% greater in 5-6 month tight-skin mice than age-matched controls, but Bladder mass, protein content, and protein concentration were similar. Tight-skin mice urinated larger volumes more frequently during the light cycle, and the Functional Bladder capacity appeared to be greater than that of controls. There was a small shift to the right of the passive length-tension curves of Bladder strips from tight-skin mice, but the shift was not statistically significant. The magnitude of active tension development was the same. The data suggest that Bladder collagen concentration does not necessarily determine Bladder capacity or compliance. It is suggested that other factors, such as the ratio of collagen subtypes or the collagemelastin ratio may have more importance for the maintenance of Bladder distension.
