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Verratti V, Mrakic-Sposta S, Moriggi M, Tonacci A, Bhandari S, Migliorelli D, Bajracharya A, Bondi D, Agrò EF, Cerretelli P. Urinary physiology and hypoxia: a pilot study of moderate-altitude trekking effects on urodynamic indexes. Am J Physiol Renal Physiol 2019; 317:F1081-F1086. [DOI: 10.1152/ajprenal.00333.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exposure to high altitude is one of the most widely used models to study the adaptive response to hypoxia in humans. However, little is known about the related effects on micturition. The present study addresses the adaptive urinary responses in four healthy adult lowlanders, comparing urodynamic indexes at Kathmandu [1,450 m above sea level (a.s.l.); K1450] and during a sojourn in Namche Bazar (3,500 m a.s.l.; NB3500). The urodynamic testing consisted of cistomanometry and bladder pressure/flow measurements. Anthropometrics, electrocardiographic, and peripheral capillary oxygen saturation data were also collected. The main findings consisted of significant reductions in bladder power at maximum urine flow by ~30%, bladder contractility index by 13%, and infused volume both at first (by 57%) and urgency sensation (by 14%) to urinate, indicating a reduced cystometric capacity, at NB3500. In addition to the urinary changes, we found that oxygen saturation, body mass index, body surface area, and median RR time were all significantly reduced at altitude. We submit that the hypoxia-related parasympathetic inhibition could be the underlying mechanism of both urodynamic and heart rate adaptive responses to high-altitude exposure. Moreover, increased diuresis and faster bladder filling at altitude may trigger the anticipation of being able to void, a common cause of urgency. We believe that the present pilot study represents an original approach to the study of urinary physiology at altitude.
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Affiliation(s)
- Vittore Verratti
- Department of Psychological Sciences, Health, and Territory, University “G. d’Annunzio” of Chieti-Pescara, Chieti, Italy
- Laboratory of Clinical and Hypoxic Physiology, University “G. d’Annunzio” of Chieti-Pescara, Chieti, Italy
| | - Simona Mrakic-Sposta
- Institute of Bioimaging and Molecular Physiology, National Research Council of Italy, Segrate, Italy
| | - Manuela Moriggi
- Institute of Bioimaging and Molecular Physiology, National Research Council of Italy, Segrate, Italy
| | - Alessandro Tonacci
- Institute of Clinical Physiology, National Research Council of Italy, Pisa, Italy
| | - Suwas Bhandari
- Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | | | | | - Danilo Bondi
- Department of Neuroscience, Imaging, and Clinical Sciences, University “G. d’Annunzio” of Chieti-Pescara, Chieti, Italy
| | - Enrico Finazzi Agrò
- Department of Surgical Sciences, University of Rome “Tor Vergata” and Unit of Urology Policlinic, Tor Vergata University Hospital, Rome, Italy
| | - Paolo Cerretelli
- Institute of Bioimaging and Molecular Physiology, National Research Council of Italy, Segrate, Italy
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Abstract
The lower urinary tract (LUT) has two functions: (1) the storage of waste products in the form of urine and (2) the elimination of those wastes through micturition. The LUT operates in a simple "on-off" fashion, either storing urine or releasing it during voiding. While this activity may seem simple, micturition is controlled by a complex set of peripheral neurons that are, in turn, coordinated by cell groups in the spinal cord, brainstem, and brain. When this careful coordination is interrupted, the control of the bladder is lost, resulting in incontinence or retention of urine. The purpose of this chapter is to review how the neural systems coordinating the activity of the lower urinary tract form neural circuits that are responsible for either maintaining continence (the storage reflex) or inducing micturition (the voiding reflex). We will also discuss the brain centers that enable higher organisms to voluntarily choose the time and place for voiding. Finally, we will discuss how defects in the pathways controlling micturition can lead to urinary incontinence and which treatments may normalize LUT function.
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Affiliation(s)
- Jonathan M Beckel
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA 19104 USA.
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Cruz Y, Downie JW. Abdominal muscle activity during voiding in female rats with normal or irritated bladder. Am J Physiol Regul Integr Comp Physiol 2005; 290:R1436-45. [PMID: 16373437 DOI: 10.1152/ajpregu.00556.2005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aims of the present study were to determine in female rats whether abdominal muscle discharges during normal voiding and to describe the effect of bladder irritation on this visceromotor activity. The sensory pathway of this reflex was also determined. Electromyograms (EMGs) indicated that in awake rats, the abdominal muscle was consistently activated during spontaneous voiding and during voiding induced by saline infusion. Similarly, in anesthetized animals, the muscle discharged during urine expulsion. The abdominal EMG activity was not abolished by hypogastric (Hgnx) or sensory pudendal neurectomy (SPdnx). SPdnx dramatically decreased the intercontraction interval and voided volume. Acetic acid infusion reduced the intercontraction interval and increased bladder contraction duration. It also reduced the pressure threshold for evoking the abdominal EMG response and increased the EMG duration and amplitude. Although SPdnx and Hgnx modified some urodynamic parameters, they did not reverse the acetic acid effect on EMG activity. Thus the afferents activating the visceromotor reflex during normal voiding and the increased reflex in response to acetic acid are probably both carried by the pelvic nerve. Abdominal muscle activity induced by bladder distension has been considered to be a pain marker. However, we conclude that in female rats, the abdominal muscle is reflexively activated during physiological urine expulsion. On the other hand, bladder irritation is marked by an exaggeration of this abdominal visceromotor reflex.
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Affiliation(s)
- Yolanda Cruz
- Dept. of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5
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Manzo J, Garcia LI, Hernandez ME, Carrillo P, Pacheco P. Neuroendocrine control of urine-marking behavior in male rats. Physiol Behav 2002; 75:25-32. [PMID: 11890949 DOI: 10.1016/s0031-9384(01)00637-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sexually experienced Wistar male rats were used to investigate (a) urine voiding in the presence of nearby estrous females and the control of such voiding by (b) steroid hormones and (c) peripheral nerves supplying the genitourinary system. The first experiment showed that males always have a low rate of urine voiding that is significantly increased when a receptive female is around. Thus, it is suggested that an airborne scent from the female stimulates the olfactory system of males, triggering urine emission to transmit sex-related messages, i.e., male rats display the well-known urine-marking behavior of mammals. The number of urine marks and sniffing to females decreased after castration, and were restored after exogenous treatment with testosterone or estradiol. The proposed hypothesis is that airborne scents from the female activate the aromatization process in nuclei of the olfactory pathway of the male, evoking a cascade of neuronal responses that finish in urine marking. Peripheral nerves supplying the genitourinary system are the viscerocutaneous branch of the pelvic nerve (Vc) and the hypogastric (Hg). Data showed that both nerves are important for the central control of urine storage and voiding. Transection of Vc almost blocked urine marking, while Hg lesion increased the number of marks. Thus, it is discussed that Vc is the most important nerve in charge of voiding the bladder, and that Hg is important for continence.
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Affiliation(s)
- J Manzo
- Instituto de Neuroetología, Universidad Veracruzana, Apartado Postal 566, Xalapa, Ver. 91001, Mexico.
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Vaughan CW, Satchell PM. Gender, bladder distension and hypogastric nerve activity in the cat. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1994; 47:59-67. [PMID: 8188985 DOI: 10.1016/0165-1838(94)90066-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In the pentobarbitone anaesthetised cat, postganglionic activity was recorded from the whole hypogastric nerve and from hypogastric filaments destined for the bladder wall during bladder distension. A gender difference was observed in whole hypogastric nerve recordings, cardiac-related activity obscuring other components in females with intact internal reproductive organs. In contrast, nerve activity in the vesical hypogastric filaments was dominated by bladder distension-related activity in both sexes. These observations suggest that bladder distension-related activity, which has a continence promoting action on the bladder detrusor muscle, is destined for the bladder wall, while the cardiac-related activity is largely destined for the uterine and vaginal vasculature.
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Affiliation(s)
- C W Vaughan
- Gordon Craig Laboratory, Department of Surgery, University of Sydney, NSW, Australia
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