scholarly journals Role of spinal GABAA receptors in pudendal inhibition of nociceptive and nonnociceptive bladder reflexes in cats

2014 ◽  
Vol 306 (7) ◽  
pp. F781-F789 ◽  
Author(s):  
Zhiying Xiao ◽  
Jeremy Reese ◽  
Zeyad Schwen ◽  
Bing Shen ◽  
Jicheng Wang ◽  
...  
Keyword(s):  
Gabaa Receptors ◽  
Bladder Capacity ◽  
Aminobutyric Acid ◽  
Saline Control ◽  
Receptor Subtype ◽  
High Dose ◽  
Multiple Threshold ◽  
Bladder Activity ◽  
Subtype A

Picrotoxin, an antagonist for γ-aminobutyric acid receptor subtype A (GABAA), was used to investigate the role of GABAA receptors in nociceptive and nonnociceptive reflex bladder activities and pudendal inhibition of these activities in cats under α-chloralose anesthesia. Acetic acid (AA; 0.25%) was used to irritate the bladder and induce nociceptive bladder overactivity, while saline was used to distend the bladder and induce nonnociceptive bladder activity. To modulate the bladder reflex, pudendal nerve stimulation (PNS) was applied at multiple threshold (T) intensities for inducing anal sphincter twitching. AA irritation significantly ( P < 0.01) reduced bladder capacity to 34.3 ± 7.1% of the saline control capacity, while PNS at 2T and 4T significantly ( P < 0.01) increased AA bladder capacity to 84.0 ± 7.8 and 93.2 ± 15.0%, respectively, of the saline control. Picrotoxin (0.4 mg it) did not change AA bladder capacity but completely removed PNS inhibition of AA-induced bladder overactivity. Picrotoxin (iv) only increased AA bladder capacity at a high dose (0.3 mg/kg) but significantly ( P < 0.05) reduced 2T PNS inhibition at low doses (0.01–0.1 mg/kg). During saline cystometry, PNS significantly ( P < 0.01) increased bladder capacity to 147.0 ± 7.6% at 2T and 172.7 ± 8.9% at 4T of control capacity, and picrotoxin (0.4 mg it or 0.03–0.3 mg/kg iv) also significantly ( P < 0.05) increased bladder capacity. However, picrotoxin treatment did not alter PNS inhibition during saline infusion. These results indicate that spinal GABAA receptors have different roles in controlling nociceptive and nonnociceptive reflex bladder activities and in PNS inhibition of these activities.

scholarly journals Sympathetic β-adrenergic mechanism in pudendal inhibition of nociceptive and non-nociceptive reflex bladder activity

2016 ◽  
Vol 311 (1) ◽  
pp. F78-F84 ◽  
Author(s):  
Brian T. Kadow ◽  
Timothy D. Lyon ◽  
Zhaocun Zhang ◽  
Vladimir Lamm ◽  
Bing Shen ◽  
...  
Keyword(s):  
Bladder Capacity ◽  
Saline Control ◽  
Hypogastric Nerve ◽  
Metabotropic Glutamate ◽  
Nociceptive Reflex ◽  
Peripheral Mechanism ◽  
Adrenergic Mechanism ◽  
Multiple Threshold ◽  
Bladder Activity

This study investigated the role of the hypogastric nerve and β-adrenergic mechanisms in the inhibition of nociceptive and non-nociceptive reflex bladder activity induced by pudendal nerve stimulation (PNS). In α-chloralose-anesthetized cats, non-nociceptive reflex bladder activity was induced by slowly infusing saline into the bladder, whereas nociceptive reflex bladder activity was induced by replacing saline with 0.25% acetic acid (AA) to irritate the bladder. PNS was applied at multiple threshold (T) intensities for inducing anal sphincter twitching. During saline infusion, PNS at 2T and 4T significantly ( P < 0.01) increased bladder capacity to 184.7 ± 12.6% and 214.5 ± 10.4% of the control capacity. Propranolol (3 mg/kg iv) had no effect on PNS inhibition, but 3-[(2-methyl-4-thiazolyl)ethynyl]pyridine (MTEP; 1–3 mg/kg iv) significantly ( P < 0.05) reduced the inhibition. During AA irritation, the control bladder capacity was significantly ( P < 0.05) reduced to ∼22% of the saline control capacity. PNS at 2T and 4T significantly ( P < 0.01) increased bladder capacity to 406.8 ± 47% and 415.8 ± 46% of the AA control capacity. Propranolol significantly ( P < 0.05) reduced the bladder capacity to 276.3% ± 53.2% (at 2T PNS) and 266.5 ± 72.4% (at 4T PNS) of the AA control capacity, whereas MTEP (a metabotropic glutamate 5 receptor antagonist) removed the residual PNS inhibition. Bilateral transection of the hypogastric nerves produced an effect similar to that produced by propranolol. This study indicates that hypogastric nerves and a β-adrenergic mechanism in the detrusor play an important role in PNS inhibition of nociceptive but not non-nociceptive reflex bladder activity. In addition to this peripheral mechanism, a central nervous system mechanism involving metabotropic glutamate 5 receptors also has a role in PNS inhibition.

scholarly journals Sympathetic afferents in the hypogastric nerve facilitate nociceptive bladder activity in cats

2019 ◽  
Vol 316 (4) ◽  
pp. F703-F711 ◽  
Author(s):  
Yan Zhang ◽  
Shun Li ◽  
Todd Yecies ◽  
Tara Morgan ◽  
Haotian Cai ◽  
...  
Keyword(s):  
Bladder Capacity ◽  
Saline Control ◽  
Pelvic Nerve ◽  
Analgesic Agent ◽  
Hypogastric Nerve ◽  
C Fibers ◽  
Pelvic Nerves ◽  
C Fiber ◽  
Bladder Activity

This study in α-chloralose-anesthetized cats revealed a role of hypogastric nerve afferent axons in nociceptive bladder activity induced by bladder irritation using 0.25% acetic acid (AA). In cats with intact hypogastric and pelvic nerves, AA irritation significantly ( P < 0.05) reduced bladder capacity to 45.0 ± 5.7% of the control capacity measured during a saline cystometrogram (CMG). In cats with the hypogastric nerves transected bilaterally, AA irritation also significantly ( P < 0.05) reduced bladder capacity, but the change was significantly smaller (capacity reduced to 71.5 ± 10.6% of saline control, P < 0.05) than that in cats with an intact hypogastric nerve. However, application of hypogastric nerve stimulation (HGNS: 20 Hz, 0.2 ms pulse width) to the central end of the transected nerves at an intensity (16 V) strong enough to activate C-fiber afferent axons facilitated the effect of AA irritation and further ( P < 0.05) reduced bladder capacity to 48.4 ± 7.4% of the saline control. This facilitation by HGNS was effective only at selected frequencies (1, 20, and 30 Hz) when the stimulation intensity was above the threshold for activating C-fibers. Tramadol (an analgesic agent) at 3 mg/kg iv completely blocked the nociceptive bladder activity and eliminated the facilitation by HGNS. HGNS did not alter non-nociceptive bladder activity induced by saline distention of the bladder. These results indicate that sympathetic afferents in the hypogastric nerve play an important role in the facilitation of the nociceptive bladder activity induced by bladder irritation that activates the silent C-fibers in the pelvic nerve.

scholarly journals Involvement of 5-HT3 receptors in pudendal inhibition of bladder overactivity in cats

2013 ◽  
Vol 305 (5) ◽  
pp. F663-F671 ◽  
Author(s):  
Zeyad Schwen ◽  
Yosuke Matsuta ◽  
Bing Shen ◽  
Jicheng Wang ◽  
James R. Roppolo ◽  
...  
Keyword(s):  
High Intensity ◽  
Bladder Capacity ◽  
Saline Control ◽  
Low Intensity ◽  
Afferent Nerves ◽  
Normal Bladder ◽  
Pudendal Neuromodulation ◽  
Bladder Symptoms ◽  
Bladder Activity

In the present study, the role of 5-HT3 receptors in pudendal neuromodulation of bladder activity and its interaction with opioid receptors were investigated in anesthetized cats. The bladder was distended with either saline to induce normal bladder activity or with 0.25% acetic acid (AA) to induce bladder overactivity. Pudendal afferent nerves were activated by 5-Hz stimulation at multiples of the threshold (T) intensity for the induction of anal twitching. AA irritation significantly reduced bladder capacity to 16.5 ± 3.3% of saline control capacity, whereas pudendal nerve stimulation (PNS) at 1.5–2 and 3–4 T restored the capacity to 82.0 ± 12% ( P = 0.0001) and 98.6 ± 15% ( P < 0.0001), respectively. Cumulative doses (1–3 mg/kg iv) of ondansetron, a 5-HT3 receptor antagonist, eliminated low-intensity (1.5–2 T) PNS inhibition and reduced high-intensity (3–4 T) PNS inhibition of bladder overactivity. During saline distention, PNS at 1.5–2 and 3–4 T significantly increased bladder capacity to 173.2 ± 26.4% ( P = 0.036) and 193.2 ± 22.5% ( P = 0.008), respectively, of saline control capacity, but ondansetron (0.003–3 mg/kg iv) did not alter PNS inhibition. Ondansetron (0.1–3 mg/kg) also significantly ( P < 0.05) increased control bladder capacity (50–200%) during either AA irritation or saline distention. In both conditions, the effects of low- and high-intensity PNS were not significantly different. After ondansetron (3 mg/kg) treatment, naloxone (1 mg/kg iv) significantly ( P < 0.05) decreased control bladder capacity (40–70%) during either AA irritation or saline distention but failed to affect PNS inhibition. This study revealed that activation of 5-HT3 receptors has a role in PNS inhibition of bladder overactivity. It also indicated that 5-HT3 receptor antagonists might be useful for the treatment of overactive bladder symptoms.

scholarly journals Propranolol, but not naloxone, enhances spinal reflex bladder activity and reduces pudendal inhibition in cats

2015 ◽  
Vol 308 (1) ◽  
pp. R42-R49 ◽  
Author(s):  
Marc J. Rogers ◽  
Zhiying Xiao ◽  
Bing Shen ◽  
Jicheng Wang ◽  
Zeyad Schwen ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Nerve Stimulation ◽  
Adrenergic Receptor ◽  
Bladder Capacity ◽  
Spinal Reflex ◽  
Saline Control ◽  
Tibial Nerve Stimulation ◽  
Bladder Activity ◽  
Propranolol Treatment

This study examined the role of β-adrenergic and opioid receptors in spinal reflex bladder activity and in the inhibition induced by pudendal nerve stimulation (PNS) or tibial nerve stimulation (TNS). Spinal reflex bladder contractions were induced by intravesical infusion of 0.25% acetic acid in α-chloralose-anesthetized cats after an acute spinal cord transection (SCT) at the thoracic T9/T10 level. PNS or TNS at 5 Hz was applied to inhibit these spinal reflex contractions at 2 and 4 times the threshold intensity (T) for inducing anal or toe twitch, respectively. During a cystrometrogram (CMG), PNS at 2T and 4T significantly ( P < 0.05) increased bladder capacity from 58.0 ± 4.7% to 85.8 ± 10.3% and 96.5 ± 10.7%, respectively, of saline control capacity, while TNS failed to inhibit spinal reflex bladder contractions. After administering propranolol (3 mg/kg iv, a β1/β2-adrenergic receptor antagonist), the effects of 2T and 4T PNS on bladder capacity were significantly ( P < 0.05) reduced to 64.5 ± 9.5% and 64.7 ± 7.3%, respectively, of the saline control capacity. However, the residual PNS inhibition (about 10% increase in capacity) was still statistically significant ( P < 0.05). Propranolol treatment also significantly ( P = 0.0019) increased the amplitude of bladder contractions but did not change the control bladder capacity. Naloxone (1 mg/kg iv, an opioid receptor antagonist) had no effect on either spinal reflex bladder contractions or PNS inhibition. At the end of experiments, hexamethonium (10 mg/kg iv, a ganglionic blocker) significantly ( P < 0.05) reduced the amplitude of the reflex bladder contractions. This study indicates an important role of β1/β2-adrenergic receptors in pudendal inhibition and spinal reflex bladder activity.

scholarly journals Differential role of opioid receptors in tibial nerve inhibition of nociceptive and nonnociceptive bladder reflexes in cats

2012 ◽  
Vol 302 (9) ◽  
pp. F1090-F1097 ◽  
Author(s):  
Changfeng Tai ◽  
Jeffrey A. Larson ◽  
P. Dafe Ogagan ◽  
Guoqing Chen ◽  
Bing Shen ◽  
...  
Keyword(s):  
Opioid Receptors ◽  
Tibial Nerve ◽  
Bladder Capacity ◽  
Saline Infusion ◽  
Saline Control ◽  
Afferent Inhibition ◽  
Urinary Tract Disorders ◽  
Acute Increase ◽  
Nerve Inhibition

Naloxone (an opioid receptor antagonist) was used to examine the role of opioid mechanisms in bladder reflexes and in somatic afferent inhibition of these reflexes by tibial nerve stimulation (TNS). Experiments were conducted in α-chloralose-anesthetized cats when the bladder was infused with saline or 0.25% acetic acid (AA). The bladder volume was measured at the first large-amplitude (>30 cmH2O) contraction during a cystometrogram and termed “estimated bladder capacity” (EBC). AA irritated the bladder, induced bladder overactivity, and significantly ( P < 0.0001) reduced EBC to 14.3 ± 1.9% of the saline control. TNS (5 Hz, 0.2 ms) at 4 and 8 times the threshold (T) intensity for inducing an observable toe movement suppressed AA-induced bladder overactivity and significantly increased EBC to 41.5 ± 9.9% (4T, P < 0.05) and 46.1 ± 7.9% (8T, P < 0.01) of the saline control. Naloxone (1 mg/kg iv) completely eliminated TNS inhibition of bladder overactivity. Naloxone (0.001–1 mg/kg iv) did not change EBC during AA irritation. However, during saline infusion naloxone (1 mg/kg iv) significantly ( P < 0.01) reduced EBC to 66.5 ± 8.1% of the control EBC. During saline infusion, TNS induced an acute increase in EBC and an increase that persisted following the stimulation. Naloxone (1 mg/kg) did not alter either type of inhibition. However, naloxone administered during the poststimulation inhibition decreased EBC. These results indicate that opioid receptors have different roles in modulation of nociceptive and nonnociceptive bladder reflexes and in somatic afferent inhibition of these reflexes, raising the possibility that opioid receptors may be a target for pharmacological treatment of lower urinary tract disorders.

scholarly journals Role of cannabinoid receptor type 1 in tibial and pudendal neuromodulation of bladder overactivity in cats

2017 ◽  
Vol 312 (3) ◽  
pp. F482-F488 ◽  
Author(s):  
Xuewen Jiang ◽  
Michelle Yu ◽  
Jamie Uy ◽  
Thomas W. Fuller ◽  
Cameron Jones ◽  
...  
Keyword(s):  
Nerve Stimulation ◽  
Cannabinoid Receptor ◽  
Bladder Capacity ◽  
Intrathecal Administration ◽  
Saline Control ◽  
Cb1 Receptors ◽  
Pudendal Neuromodulation ◽  
Bladder Disorders

The role of cannabinoid type 1 (CB1) receptors in tibial and pudendal neuromodulation of bladder overactivity induced by intravesical infusion of 0.5% acetic acid (AA) was determined in α-chloralose anesthetized cats. AA irritation significantly ( P < 0.01) reduced bladder capacity to 36.6 ± 4.8% of saline control capacity. Tibial nerve stimulation (TNS) at two or four times threshold (2T or 4T) intensity for inducing toe movement inhibited bladder overactivity and significantly ( P < 0.01) increased bladder capacity to 69.2 ± 9.7 and 79.5 ± 7.2% of saline control, respectively. AM 251 (a CB1 receptor antagonist) administered intravenously at 0.03 or 0.1 mg/kg significantly ( P < 0.05) reduced the inhibition induced by 2T or 4T TNS, respectively, without changing the prestimulation bladder capacity. However, intrathecal administration of AM 251 (0.03 mg) to L7 spinal segment had no effect on TNS inhibition. Pudendal nerve stimulation (PNS) also inhibited bladder overactivity induced by AA irritation, but AM 251 at 0.01–1 mg/kg iv had no effect on PNS inhibition or the prestimulation bladder capacity. These results indicate that CB1 receptors play an important role in tibial but not pudendal neuromodulation of bladder overactivity and the site of action is not within the lumbar L7 spinal cord. Identification of neurotransmitters involved in TNS or PNS inhibition of bladder overactivity is important for understanding the mechanisms of action underlying clinical application of neuromodulation therapies for bladder disorders.

Expression of gamma-aminobutyric acid receptor (subtype A) in prostate cancer

2008 ◽  
Vol 47 (8) ◽  
pp. 1546-1550 ◽  
Author(s):  
Mansoor Abdul ◽  
Shawntae D. Mccray ◽  
Naseema M. Hoosein
Keyword(s):  
Prostate Cancer ◽  
Aminobutyric Acid ◽  
Receptor Subtype ◽  
Gamma Aminobutyric Acid ◽  
Acid Receptor ◽  
Subtype A

Pre- and post-synaptic mechanisms regulating the clustering of type A γ-aminobutyric acid receptors (GABAA receptors)

2003 ◽  
Vol 31 (4) ◽  
pp. 889-892 ◽  
Author(s):  
J.-M. Fritschy ◽  
C. Schweizer ◽  
I. Brünig ◽  
B. Lüscher
Keyword(s):  
Neuronal Activity ◽  
Protein Complex ◽  
Gabaa Receptors ◽  
Synapse Formation ◽  
Type A ◽  
Aminobutyric Acid ◽  
Proper Function ◽  
Gabaergic Synapses ◽  
Synaptic Mechanisms

Postsynaptic clustering of GABAA (type A γ-aminobutyric acid) receptors is essential to ensure proper function of GABAergic synapses. This process is initiated during synapse formation and is maintained throughout life. The tubulin-associated protein gephyrin is required for clustering of GABAA receptors, but its specific role in this process is not understood. A second protein associated selectively with GABAA receptors at postsynaptic sites is dystrophin. It is present in a subset of GABAergic synapses along with several partners, forming the dystrophin-associated protein complex. In this review, we discuss recent advances in the role of neuronal activity and trans-synaptic signaling for the clustering of gephyrin and dystrophin during synaptogenesis and on the role of these proteins for plasticity and maintenance of mature synapses.

The physiological properties and therapeutic potential of α5-GABAA receptors

2009 ◽  
Vol 37 (6) ◽  
pp. 1334-1337 ◽  
Author(s):  
Loren J. Martin ◽  
Robert P. Bonin ◽  
Beverley A. Orser
Keyword(s):  
Science Fiction ◽  
Gabaa Receptors ◽  
Therapeutic Potential ◽  
Memory Performance ◽  
Aminobutyric Acid ◽  
Pharmacological Properties ◽  
Physiological Properties ◽  
Drug Treatments ◽  
Subtype A ◽  
Memory Enhancing

The notion that drug treatments can improve memory performance has moved from the realm of science fiction to that of serious investigation. A popular working hypothesis is that cognition can be improved by altering the balance between excitatory and inhibitory neurotransmission. This review focuses on the unique physiological and pharmacological properties of GABAARs [GABA (γ-aminobutyric acid) subtype A receptors] that contain the α5 subunit (α5-GABAAR), as these receptors serve as candidate targets for memory-enhancing drugs.

scholarly journals Sex difference in the contribution of GABAB receptors to tibial neuromodulation of bladder overactivity in cats

2017 ◽  
Vol 312 (3) ◽  
pp. R292-R300 ◽  
Author(s):  
Thomas W. Fuller ◽  
Xuewen Jiang ◽  
Utsav Bansal ◽  
Vladimir Lamm ◽  
Bing Shen ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Sex Difference ◽  
Pudendal Nerve ◽  
Bladder Capacity ◽  
Gabab Receptors ◽  
Aminobutyric Acid ◽  
Intravesical Administration ◽  
Subtype B ◽  
Pudendal Neuromodulation

This study investigated the role of γ-aminobutyric acid subtype B (GABAB) receptors in tibial and pudendal neuromodulation of bladder overactivity induced by intravesical administration of dilute (0.5%) acetic acid (AA) in α-chloralose-anesthetized cats. To inhibit bladder overactivity, tibial or pudendal nerve stimulation (TNS or PNS) was applied at 5 Hz and two or four times threshold (T) intensity for inducing toe or anal sphincter twitch. TNS at 2T or 4T intensity significantly ( P < 0.05) increased the bladder capacity to 173.8 ± 16.2 or 198.5 ± 24.1%, respectively, of control capacity. Meanwhile, PNS at 2T or 4T intensity significantly ( P < 0.05) increased the bladder capacity to 217 ± 18.8 and 221.3 ± 22.3% of control capacity, respectively. CGP52432 (a GABAB receptor antagonist) at intravenous dosages of 0.1–1 mg/kg completely removed the TNS inhibition in female cats but had no effect in male cats. CGP52432 administered intravenously also had no effect on control bladder capacity or the pudendal inhibition of bladder overactivity. These results reveal a sex difference in the role of GABAB receptors in tibial neuromodulation of bladder overactivity in cats and that GABAB receptors are not involved in either pudendal neuromodulation or irritation-induced bladder overactivity.

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