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Liu J, Wang C, Wang W, Ding N, Liu J, Liu H, Wen J, Sun W, Zu S, Zhang X, Yan J. Activation of Piezo1 or TRPV2 channels inhibits human ureteral contractions via NO release from the mucosa. Front Pharmacol 2024; 15:1410565. [PMID: 38989142 PMCID: PMC11233528 DOI: 10.3389/fphar.2024.1410565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 05/28/2024] [Indexed: 07/12/2024] Open
Abstract
We aimed to investigate the expression and motor modulatory roles of several mechano-sensitive channels (MSCs) in human ureter. Human proximal ureters were obtained from eighty patients subjected to nephrectomy. Expression of MSCs at mRNA, protein and functional levels were examined. Contractions of longitudinal ureter strips were recorded in organ bath. A fluorescent probe Diaminofluoresceins was used to measure nitric oxide (NO). RT-PCR analyses revealed predominant expression of Piezo1 and TRPV2 mRNA in intact ureter and mucosa. Immunofluorescence assays indicate proteins of MSCs (Piezo1/Piezo2, TRPV2 and TRPV4) were mainly distributed in the urothelium. Ca2+ imaging confirmed functional expression of TRPV2, TRPV4 and Piezo1 in cultured urothelial cells. Specific agonists of Piezo1 (Yoda1, 3-300 μM) and TRPV2 (cannabidiol, 3-300 μM) attenuated the frequency of ureteral contractions in a dose-dependent manner while the TRPV4 agonist GSK1016790A (100 nM-1 μM) exerted no effect. The inhibitory effects of Piezo1 and TRPV2 agonists were significantly blocked by the selective antagonists (Dooku 1 for Piezo1, Tranilast for TRPV2), removal of the mucosa, and pretreatment with NO synthase inhibitor L-NAME (10 μM). Yoda1 (30 μM) and cannabidiol (50 μM) increased production of NO in cultured urothelial cells. Our results suggest that activation of Piezo1 or TRPV2 evokes NO production and release from mucosa that may mediate mechanical stimulus-induced reduction of ureter contractions. Our findings support the idea that targeting Piezo1 and TRPV2 channels may be a promising pharmacological strategy for ureter stone passage or colic pain relief.
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Affiliation(s)
- Jianing Liu
- Department of Kidney Transplantation, Multidisciplinary Innovation Center for Nephrology, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Cong Wang
- Department of Urology, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Wenyu Wang
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Ning Ding
- Department of Urology, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Jiaxin Liu
- Department of Kidney Transplantation, Multidisciplinary Innovation Center for Nephrology, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Hanwen Liu
- Department of Urology, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Jiliang Wen
- Department of Urology, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Wendong Sun
- Department of Urology, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Shulu Zu
- Department of Urology, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Xiulin Zhang
- Department of Urology, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Jieke Yan
- Department of Kidney Transplantation, Multidisciplinary Innovation Center for Nephrology, The Second Hospital of Shandong University, Jinan, Shandong, China
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O'Meara S, Cunnane EM, Croghan SM, Cunnane CV, Walsh MT, O'Brien FJ, Davis NF. Mechanical characteristics of the ureter and clinical implications. Nat Rev Urol 2024; 21:197-213. [PMID: 38102385 DOI: 10.1038/s41585-023-00831-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2023] [Indexed: 12/17/2023]
Abstract
The ureteric wall is a complex multi-layered structure. The ureter shows variation in passive mechanical properties, histological morphology and insertion forces along the anatomical length. Ureter mechanical properties also vary depending on the direction of tensile testing and the anatomical region tested. Compliance is greatest in the proximal ureter and lower in the distal ureter, which contributes to the role of the ureter as a high-resistance sphincter. Similar to other human tissues, the ureteric wall remodels with age, resulting in changes to the mechanical properties. The passive mechanical properties of the ureter vary between species, and variation in tissue storage and testing methods limits comparison across some studies. Knowledge of the morphological and mechanical properties of the ureteric wall can aid in understanding urine transport and safety thresholds in surgical techniques. Indeed, various factors alter the forces required to insert access sheaths or scopes into the ureter, including sheath diameter, safety wires and medications. Future studies on human ureteric tissue both in vivo and ex vivo are required to understand the mechanical properties of the ureter and how forces influence these properties. Testing of instrument insertion forces in humans with a focus on defining safe upper limits and techniques to reduce trauma are also needed. Last, evaluation of dilatation limits in the mid and proximal ureter and clarification of tensile strength anisotropy in human specimens are necessary.
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Affiliation(s)
- Sorcha O'Meara
- Department of Surgery, Royal College of Surgeons of Ireland (RCSI), Dublin, Ireland.
- Department of Urology, Blackrock Clinic, Blackrock, Co., Dublin, Ireland.
| | - Eoghan M Cunnane
- Biomaterials Cluster, Bernal Institute, University of Limerick, Limerick, Ireland
- School of Engineering, University of Limerick, Limerick, Ireland
| | - Stefanie M Croghan
- Department of Surgery, Royal College of Surgeons of Ireland (RCSI), Dublin, Ireland
- Department of Urology, Blackrock Clinic, Blackrock, Co., Dublin, Ireland
| | - Connor V Cunnane
- Biomaterials Cluster, Bernal Institute, University of Limerick, Limerick, Ireland
- School of Engineering, University of Limerick, Limerick, Ireland
| | - Michael T Walsh
- Biomaterials Cluster, Bernal Institute, University of Limerick, Limerick, Ireland
- School of Engineering, University of Limerick, Limerick, Ireland
| | - Fergal J O'Brien
- Tissue Engineering Research Group, Department of Anatomy and Regenerative Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- Trinity Centre for Biomedical Engineering, Trinity College Dublin, Dublin, Ireland
- Advanced Materials and Bioengineering Research Centre (AMBER), RCSI and TCD, Dublin, Ireland
| | - Niall F Davis
- Department of Surgery, Royal College of Surgeons of Ireland (RCSI), Dublin, Ireland
- Department of Urology, Blackrock Clinic, Blackrock, Co., Dublin, Ireland
- Department of Urology and Transplant Surgery, Beaumont Hospital, Dublin, Ireland
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Abbasian S, Maddahian R. Numerical analysis of an obstacle motion in the human ureter using the dynamic mesh approach. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3800. [PMID: 38211948 DOI: 10.1002/cnm.3800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 12/07/2023] [Indexed: 01/13/2024]
Abstract
Peristalsis is a common motion in various biological systems, especially the upper urinary tract, where it plays a pivotal role in conveying urine from the kidneys to the bladder. Using computational fluid dynamics, this study aims to investigate the effect of various peristaltic parameters on the motion of an obstacle through a two-dimensional ureter. Methodologically, Incompressible Navier-Stokes equations were utilized as the fluid domain's governing equations, and the Dynamic Mesh method (DM) was employed to simulate the peristaltic and obstacle motion. The peristaltic motion was modeled by a sinusoidal contraction wave propagating alongside the ureter at the physiological speed, and the motion of the obstruction through the ureter, which is caused by the fluid forces applied on its surface, was explored using the equation of Newton's second law. Various test cases of different shapes and sizes were supposed as kidney stones to understand the influence of the peristalsis properties on the stone removal process. The results show that the motion of the kidney stone is highly influenced by the gradient pressure force applied to its surface in the fluid domain. Moreover, investigating the effects of the peristaltic physical properties on the obstacle's motion indicates that the stone's motion is dependent on these parameters. Furthermore, this analysis provides insight into the peristaltic motion effects, assisting physicians in developing new medicines to facilitate the kidney stone removal process based on its shape and size.
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Affiliation(s)
- Saman Abbasian
- Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
| | - Reza Maddahian
- Faculty of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
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Kalayeh K, Fowlkes JB, Xie H, Schultz WW, Sack BS. Peristalsis prevents ureteral dilation. Neurourol Urodyn 2024; 43:258-266. [PMID: 37961019 DOI: 10.1002/nau.25332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 10/16/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023]
Abstract
PURPOSE The etiology of ureteral dilation in primary nonrefluxing, nonobstructing megaureters is still not well understood. Impaired ureteral peristalsis has been theorized as one of the contributing factors. However, ureteral peristalsis and its "normal" function is not well defined. In this study, using mathematical modeling techniques, we aim to better understand how ureteral peristalsis works. This is the first model to consider clinically observed, back-and-forth, cyclic wall longitudinal motion during peristalsis. We hypothesize that dysfunctional ureteral peristalsis, caused by insufficient peristaltic amplitudes (e.g., circular muscle dysfunction) and/or lack of ureteral wall longitudinal motion (e.g., longitudinal muscle dysfunction), promotes peristaltic reflux (i.e., retrograde flow of urine during an episode of peristalsis) and may result in urinary stasis, urine accumulation, and consequent dilation. METHODS Based on lubrication theory in fluid mechanics, we developed a two-dimensional (planar) model of ureteral peristalsis. In doing so, we treated ureteral peristalsis as an infinite train of sinusoidal waves. We then analyzed antegrade and retrograde flows in the ureter under different bladder-kidney differential pressure and peristalsis conditions. RESULTS There is a minimum peristaltic amplitude required to prevent peristaltic reflux. Ureteral wall longitudinal motion decreases this minimum required amplitude, increasing the nonrefluxing range of peristaltic amplitudes. As an example, for a normal bladder-kidney differential pressure of 5 cmH2 O, ureteral wall longitudinal motion increases nonrefluxing range of peristaltic amplitude by 65%. Additionally, ureteral wall longitudinal motion decreases refluxing volumetric flow rates. For a similar normal bladder pressure example of 5 cmH2 O, refluxing volumetric flow rate decreases by a factor of 18. Finally, elevated bladder pressure, not only increases the required peristaltic amplitude for reflux prevention but it increases maximum refluxing volumetric flow rates. For the case without wall longitudinal motion, as bladder-kidney differential pressure increases from 5 to 40 cmH2 O, minimum required peristaltic amplitude to prevent reflux increases by 40% while the maximum refluxing volumetric flow rate increases by approximately 100%. CONCLUSION The results presented in this study show how abnormal ureteral peristalsis, caused by the absence of wall longitudinal motion and/or lack of sufficient peristaltic amplitudes, facilitates peristaltic reflux and retrograde flow. We theorize that this retrograde flow can lead to urinary stasis and urine accumulation in the ureters, resulting in ureteral dilation seen on imaging studies and elevated infection risk. Our results also show how chronically elevated bladder pressures are more susceptible to such refluxing conditions that could lead to ureteral dilation.
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Affiliation(s)
- Kourosh Kalayeh
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - J Brian Fowlkes
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Haotian Xie
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - William W Schultz
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Bryan S Sack
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
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Ragoori DR, Shanti D, Sharma G, Enganti B, Bendigeri T, Syed Md. G, Kondakindi PR, Chiruvella M. Role of Retrograde Intrarenal Surgery in the Management of Diabetic Renal Papillary Necrosis. J Endourol 2022; 36:1399-1404. [DOI: 10.1089/end.2022.0175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Deepak Reddy Ragoori
- Asian Institute of Nephrology and Urology, 519389, Urology, 6-3-562/A, behind MORE megamart, Errum Manzil, Hyderabad, Telangana, India, 500082,
| | - Darga Shanti
- Asian Institute of Nephrology and Urology, 519389, Urology, errumanzil, hyderabad, Hyderabad, Telangana, India, 500082
| | - Gaurav Sharma
- Asian Institute of Nephrology and Urology, 519389, Urology, Hyderabad, Telangana, India
| | - Bhavatej Enganti
- Asian Institute of Nephrology and Urology, 519389, Urology, Hyderabad, Telangana, India
| | - Taif Bendigeri
- Asian Institute of Nephrology and Urology, 519389, Urology, Hyderabad, Telangana, India
| | - Ghouse Syed Md.
- Asian Institute of Nephrology and Urology, 519389, Urology, Hyderabad, Telangana, India
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Mao C, Peng C, Li S, Chen L, You M, Fang K, Xiang S, Su Y. Quantitative evaluation of upper urinary tract pump function in pigs with acute unilateral lower ureteral obstruction by 640-slice dynamic volume CT. BMC Urol 2021; 21:118. [PMID: 34474669 PMCID: PMC8414779 DOI: 10.1186/s12894-021-00887-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 08/20/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It is a challenging problem to differentiate obstructive hydronephrosis from noninvasive evaluation of renal pelvis and ureteral motility in patients. The purpose of this study was to explore the value of 640-slice dynamic volume CT (DVCT) in the quantitative measurement of upper urinary tract (UUT) pump function after acute unilateral lower ureteral obstruction in pigs. METHODS In this study, a perfusion pig model was constructed by constant pressure perfusion testing of the renal pelvis and left nephrostomy. The perfusion and pressure measuring devices were connected to create a state of no obstruction and acute obstruction of the lower part of the left ureter. After successful modelling, continuous dynamic volume scanning of the bilateral renal excretion phase was performed with 640-slice DVCT, and pump functions of the renal pelvis and part of the upper ureter were calculated and analysed. No obstruction or acute obstruction of the lower part of the left ureter was observed. Pump functions of the renal pelvis and part of the upper ureter were determined. RESULTS The results showed that after LUUT fistulostomy, the time difference between the average UUT volume and positive volume value increased gradually, and the calculated flow velocity decreased, which was significantly different from that of the RUUT. The volume difference of the LUUT increased significantly in mild obstruction. In the bilateral control, the volume change rate of the LUUT increased with mild obstruction and decreased with severe obstruction, and there was a significant difference between the left and right sides. CONCLUSION The continuous dynamic volume scan and measurement of 640-slice DVCT can obtain five pump function datasets of UUT in pigs with acute lower ureteral obstruction.
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Affiliation(s)
- Chongwen Mao
- Department of Radiology, The Fourth Affiliated Hospital of Kunming Medical University, #176 Qingnian Road, Kunming, 650021, Yunnan, China
| | - Cong Peng
- Department of Radiology, The Central Hospital of Wuhan, The Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Song Li
- Department of Urology, The Fourth Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Liling Chen
- Department of Clinical Skills Center, The Kunming Medical University, Kunming, Yunnan, China
| | - Mengjing You
- Department of Radiology, The Fourth Affiliated Hospital of Kunming Medical University, #176 Qingnian Road, Kunming, 650021, Yunnan, China
| | - Kewei Fang
- Department of Urology, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Shutian Xiang
- Department of Radiology, The Fourth Affiliated Hospital of Kunming Medical University, #176 Qingnian Road, Kunming, 650021, Yunnan, China
| | - Yunshan Su
- Department of Radiology, The Fourth Affiliated Hospital of Kunming Medical University, #176 Qingnian Road, Kunming, 650021, Yunnan, China.
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Sokolis DP. Alterations with age in the biomechanical behavior of human ureteral wall: Microstructure-based modeling. J Biomech 2020; 109:109940. [PMID: 32807335 DOI: 10.1016/j.jbiomech.2020.109940] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 06/11/2020] [Accepted: 07/02/2020] [Indexed: 02/02/2023]
Abstract
The human ureters have not been thoroughly explored from the biomechanics perspective, despite the wealth of such data for other soft-tissue types. This study was motivated by the need to use relevant biomechanical data from human ureters and microstructure-based material formulations for simulations of ureteral peristalsis and stenting. Our starting choice was the four-fiber family model that has proven its validity as a descriptor of the multiaxial response of cardiovascular tissues. The degree of model complexity, required for rigorous fits to passive quasi-static pressure-diameter-force data at several axial stretches, was systematically investigated. Ureteral segments from sixteen human autopsy subjects were evaluated. A diagonal and axial family model allowed equally-good fits as the full model for all age groups and ureteral regions; considerably better than those allowed by the phenomenological Fung-type model whose root-mean-square error of fitting was three-fold greater. This reduced model mimicked the structure seen in histologic sections, namely plentiful diagonal collagen fibers in the lamina propria and axial fibers in the muscle and adventitia. The paucity of elastin fibers and mixed muscle orientation justified the use of isotropic muscle-dominated matrix with small neo-Hookean parameter values. The significantly thicker lamina propria in the lower than the upper ureter of young subjects (312 ± 27 vs. 232 ± 26 μm; mean ± standard error) corroborated the significant regional differences in diagonal-fiber family parameter values. The significant muscle thickening with age (upper ureter: 373 ± 48 vs. 527 ± 67 μm; middle: 388 ± 29 vs. 575 ± 69 μm; lower: 440 ± 21 vs. 602 ± 71 μm) corroborated the significant age-related increase in axial-fiber family parameter values.
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Affiliation(s)
- Dimitrios P Sokolis
- Laboratory of Biomechanics, Center of Clinical, Experimental Surgery, and Translational Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece.
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Sokolis DP. In vitro study of age-related changes in human ureteral failure properties according to region, direction, and layer. Proc Inst Mech Eng H 2019; 233:570-583. [PMID: 30922180 DOI: 10.1177/0954411919839891] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Knowledge of the capacity of the ureteral wall to withstand urodynamic or external stresses is essential to understand ureteral injury and rupture that mostly occur following trauma, but may also be secondary to obstructive uropathy. It has clinical significance as well in the prevention of iatrogenic injury, for example, during ureteroscopy, but no information is available with regard to the age-related failure properties and regional differences have not been systematically described. Uniaxial tensile testing was performed on 166 ureteral rings and strips from 21 humans free of overt urologic disease; histological evaluation was performed. The degree of layer participation to the intact wall failure stress (=tissue strength), peak elastic modulus (=stiffness), and failure stretch (=extensibility) was assessed by examining layer-specific ruptures in the stress-stretch data. Failure stress at and peak elastic modulus before the first (muscle/adventitial) rupture correlated inversely less with age ( p < 0.05 in few regions/directions) than failure stress at the second (mucosal) rupture ( p < 0.05 in the middle and lower ureter), consistent with the decreased mucosal thickness in ≥50-year-old subjects. Failure stretch at both ruptures did not correlate with age ( p > 0.05 in most regions/directions), paralleling elastin content. Correlations with age were more significant in females than males. Failure stress at the second rupture point was higher ( p < 0.05) distally in <50-year-old but not in ≥50-year-old subjects, justified by the increased collagen distally in the former. Directional differences in failure stretches ( p < 0.05 at all ages/regions/genders) were justified by preferentially axial collagen reinforcement. The presented results may establish the foundation for computational models of iatrogenic/accidental ureteral trauma.
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Affiliation(s)
- Dimitrios P Sokolis
- Laboratory of Biomechanics, Center of Clinical, Experimental Surgery, and Translational Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
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Kazaryan KV, Danielyan MA, Chibukhchyan RG, Margaryan SG. Histamine-Mediated Regulation of Electrical Activity during the Bladder–Urethra Interaction in Rats. J EVOL BIOCHEM PHYS+ 2018. [DOI: 10.1134/s0022093018010064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Kazaryan KV, Chibukhchyan RG, Margaryan SG. Characterization of spontaneous electrical activity of the urinary tract: Ureter, bladder, urethra. J EVOL BIOCHEM PHYS+ 2017. [DOI: 10.1134/s002209301704007x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Guru KA. Editorial Comment. J Urol 2017; 198:1105. [PMID: 28801260 DOI: 10.1016/j.juro.2017.05.099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Khurshid A Guru
- Department of Urology, Roswell Park Cancer Institute, Buffalo, New York
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Roshani H, Weltings S, Dabhoiwala NF, Lamers WH. Pharmacological modulation of ureteric peristalsis in a chronically instrumented conscious pig model: effect of adrenergic and nitrergic modulation. World J Urol 2015; 34:747-54. [PMID: 26276150 DOI: 10.1007/s00345-015-1663-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 07/21/2015] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To evaluate the role of adrenergic and nitrergic signaling on ureteric peristaltic frequency and contraction force in vivo using a large animal model. METHODS Twelve female pigs (72 ± 4 kg) were chronically instrumented with an electronic pressure-monitoring catheter in the right ureter. Nephrostomy, cystostomy, and arterial and venous catheters were left in situ. Ureteral peristalsis was recorded before and after the administration of propranolol, isoprenaline, doxazosin, urapidil, phenylephrine, LNNA (Nω-nitro-L-arginine), and L-arginine. RESULTS α1-Adrenergic receptor stimulation resulted in an increased P max and peristaltic frequency. However, α1-inhibition decreased P max alone. Similarly, β-adrenergic stimulation decreased P max and peristaltic frequency, whereas β-inhibition increased only P max. LNNA administration increased P max in the distal ureter and hydrostatic pressure in the pyelocalyceal system. L-Arginine did not affect P max or frequency, but resulted in a significantly higher diuresis. Either agonist or antagonist of NO did not affect peristaltic frequency and length of contraction. CONCLUSIONS Activation of α- and β-adrenergic receptors, respectively, stimulates and inhibits ureteric peristalsis. The biological effect of NO on ureteric motility is regionally determined and corresponds to the distribution of NOS-positive nerves. Inhibition of NOS activity increases P max in the distal ureter and tonic activity of the ureteric muscle resulting in higher hydrostatic pressure in the renal pelvis.
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Affiliation(s)
- H Roshani
- Department of Urology, Haga Teaching Hospital, The Hague, The Netherlands
| | - S Weltings
- HagaZiekenhuis, Leyweg 275, The Hague, The Netherlands.
- Department of Urology, Haga Teaching Hospital, The Hague, The Netherlands.
| | - N F Dabhoiwala
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Amsterdam, The Netherlands
| | - W H Lamers
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Amsterdam, The Netherlands
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Sadananda P, Drake MJ, Paton JFR, Pickering AE. An exploration of the control of micturition using a novel in situ arterially perfused rat preparation. Front Neurosci 2011; 5:62. [PMID: 21625609 PMCID: PMC3097374 DOI: 10.3389/fnins.2011.00062] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Accepted: 04/18/2011] [Indexed: 12/12/2022] Open
Abstract
Our goal was to develop and refine a decerebrate arterially perfused rat (DAPR) preparation that allows the complete bladder filling and voiding cycle to be investigated without some of the restrictions inherent with in vivo experimentation [e.g., ease and speed of set up (30 min), control over the extracellular milieu and free of anesthetic agents]. Both spontaneous (naturalistic bladder filling from ureters) and evoked (in response to intravesical infusion) voids were routinely and reproducibly observed which had similar pressure characteristics. The DAPR allows the simultaneous measurement of bladder intra-luminal pressure, external urinary sphincter-electromyogram (EUS-EMG), pelvic afferent nerve activity, pudendal motor activity, and permits excellent visualization of the entire lower urinary tract, during typical rat filling and voiding responses. The voiding responses were modulated or eliminated by interventions at a number of levels including at the afferent terminal fields (intravesical capsaicin sensitization-desensitization), autonomic (ganglion blockade with hexamethonium), and somatic motor (vecuronium block of the EUS) outflow and required intact brainstem/hindbrain-spinal coordination (as demonstrated by sequential hindbrain transections). Both innocuous (e.g., perineal stimulation) and nociceptive (tail/paw pinch) somatic stimuli elicited an increase in EUS-EMG indicating intact sensory feedback loops. Spontaneous non-micturition contractions were observed between fluid infusions at a frequency and amplitude of 1.4 ± 0.9 per minute and 1.4 ± 0.3 mmHg, respectively and their amplitude increased when autonomic control was compromised. In conclusion, the DAPR is a tractable and useful model for the study of neural bladder control showing intact afferent signaling, spinal and hindbrain co-ordination and efferent control over the lower urinary tract end organs and can be extended to study bladder pathologies and trial novel treatments.
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Affiliation(s)
- Prajni Sadananda
- School of Physiology and Pharmacology, University of BristolBristol, UK
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Rasidovic D, Kearney D, Boyle KM, Bund S. The assessment of rat ureteral pressure generationin vitro:regional heterogeneity and influence of distending pressure. ACTA ACUST UNITED AC 2010; 97:307-15. [DOI: 10.1556/aphysiol.97.2010.3.7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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