scholarly journals Comprehensive phenotyping of group III and IV muscle afferents in mouse

2013 ◽  
Vol 109 (9) ◽  
pp. 2374-2381 ◽  
Author(s):  
Michael P. Jankowski ◽  
Kristofer K. Rau ◽  
Katrina M. Ekmann ◽  
Collene E. Anderson ◽  
H. Richard Koerber
Keyword(s):  
Spinal Cord ◽  
Functional Properties ◽  
Transient Receptor Potential ◽  
Ex Vivo ◽  
Receptor Potential ◽  
Muscle Afferents ◽  
Transient Receptor Potential Vanilloid ◽  
Sensory Afferents ◽  
Group Iii ◽  
Concentration Levels

While much is known about the functional properties of cutaneous nociceptors, relatively little is known about the comprehensive functional properties of group III and IV muscle afferents. We have developed a mouse ex vivo forepaw muscle, median and ulnar nerve, dorsal root ganglion (DRG), spinal cord recording preparation to examine the functional response properties, neurochemical phenotypes, and spinal projections of individual muscle afferents. We found that the majority of group III and IV muscle afferents were chemosensitive (52%) while only 34% responded to mechanical stimulation and fewer (32%) responded to thermal stimuli. The chemosensitive afferents could be grouped into those that responded to a “low”-metabolite mixture containing amounts of lactate and ATP at pH 7.0 simulating levels observed in muscle during exercise (metaboreceptors) and a “high”-metabolite mixture containing lactic acid concentrations and ATP at pH 6.6 mimicking levels observed during ischemic contractions (metabo-nociceptors). While the majority of the metabo-nociceptive fibers responding to the higher concentration levels were found to contain acid-sensing ion channel 3 (ASIC3) and/or transient receptor potential vanilloid type 1 (TRPV1), metaboreceptors responding to the lower concentration levels lacked these receptors. Anatomically, group III muscle afferents were found to have projections into laminae I and IIo, and deeper laminae in the spinal cord, while all functional types of group IV muscle afferents projected primarily into both laminae I and II. These results provide novel information about the variety of sensory afferents innervating the muscle and provide insight into the types of fibers that may exhibit plasticity after injuries.

scholarly journals Novel Potentials of the DPP-4 Inhibitor Sitagliptin against Ischemia-Reperfusion (I/R) Injury in Rat Ex-Vivo Heart Model

2018 ◽  
Vol 19 (10) ◽  
pp. 3226 ◽  
Author(s):  
Amin Al-awar ◽  
Nikoletta Almási ◽  
Renáta Szabó ◽  
Istvan Takacs ◽  
Zsolt Murlasits ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Trp Channels ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Oral Treatment ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Dipeptidyl Peptidase 4 ◽  
Regional Ischemia ◽  
Transient Receptor

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of oral anti-diabetic drugs, implicated in pleiotropic secondary cardioprotective effects. The aim of the study was to unveil the unknown and possible cardioprotective targets that can be exerted by sitagliptin (Sitg) against ischemia-reperfusion (I/R) injury. Male wistar rats received 2 weeks’ Sitg oral treatment of different doses (25, 50, 100, and 150 mg/kg/day), or saline as a Control. Hearts were then isolated and subjected to two different I/R injury protocols: 10 min perfusion, 45 min regional ischemia, and 120 min reperfusion for infarct size (IS) measurement, or: 10 min perfusion, 45 min regional ischemia and 10 min reperfusion for biochemical analysis: nitric oxide synthases (NOSs) and DPP-4 activity, glucagon-like peptide-1 (GLP-1), Calcium, transient receptor potential vanilloid (TRPV)-1 and calcitonin gene-related peptide (CGRP) levels, transient receptor potential canonical (TRPC)-1 and e-NOS protein expression. NOS inhibitor (l-NAME) and TRPV-1 inhibitor (Capsazepine) were utilized to confirm the implication of both signaling mechanisms in DPP-4 inhibition-induced at the level of IS. Findings show that Sitg (50 mg) resulted in significant decrease in IS and DPP-4 activity, and significant increase in GLP-1, NOS activity, e-NOS expression, TRPV-1 level and TRPC-1 expression, compared to controls. Results of CGRP are in line with TRPV-1, as a downstream regulatory effect. NOS system and transient receptor potential (TRP) channels can contribute to DPP-4 inhibition-mediated cardioprotection against I/R injury using Sitagliptin.

scholarly journals TRPV1 (Transient Receptor Potential Vanilloid 1) Sensitization of Skeletal Muscle Afferents in Type 2 Diabetic Rats With Hyperglycemia

Hypertension ◽  
2021 ◽  
Author(s):  
Rie Ishizawa ◽  
Han-Kyul Kim ◽  
Norio Hotta ◽  
Gary A. Iwamoto ◽  
Jere H. Mitchell ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Dorsal Root Ganglia ◽  
Dorsal Root ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Muscle Afferents ◽  
Group Iv ◽  
Transient Receptor Potential Vanilloid ◽  
Transient Receptor

The blood pressure response to exercise is exaggerated in type 2 diabetes (T2D). However, the underlying mechanisms remain unclear. It is hypothesized that one mechanism mediating the potentiated cardiovascular response in T2D is the sensitization of chemically sensitive afferent neurons by activation of metaboreceptors. To test this hypothesis, we examined TRPV1 (transient receptor potential vanilloid 1)-induced cardiovascular responses in vivo and muscle afferent discharge ex vivo in T2D rats. Additionally, TRPV1 and PKC (protein kinase C) protein levels in dorsal root ganglia subserving skeletal muscle were assessed. For 14 to 16 weeks, Sprague-Dawley rats were given either a normal diet (control) or a high-fat diet in combination with a low dose (35 and 25 mg/kg) of streptozotocin (T2D). Administration of capsaicin, TRPV1 agonist, in hindlimb evoked significantly greater increases in mean arterial pressure and renal sympathetic nerve activity in decerebrated T2D than control. In a muscle-nerve preparation, the discharge to capsaicin exposure in group IV afferents isolated from T2D was likewise significantly augmented at a magnitude that was proportional to glucose concentration. Moreover, the discharge to capsaicin was potentiated by acute exposure of group IV afferents to a high-glucose environment. T2D showed significantly increased phospholyrated-TRPV1 and -PKCα levels in dorsal root ganglia neurons as compared with control. These findings suggest that group IV muscle afferents are sensitized by PKC-induced TRPV1 overactivity in early stage T2D with hyperglycemia and, thereby, may contribute to the potentiated circulatory response to TRPV1 activation in the disease.

Antihyperalgesic effects of vanilloid-1 and bradykinin-1 receptor antagonists following spinal cord injury in rats

2007 ◽  
Vol 6 (5) ◽  
pp. 420-424 ◽  
Author(s):  
Sharad Rajpal ◽  
Tiffany A. Gerovac ◽  
Nicholas A. Turner ◽  
Jessica I. Tilghman ◽  
Bradley K. Allcock ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Transient Receptor Potential ◽  
Treatment Strategies ◽  
Thermal Hyperalgesia ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Cord Injury ◽  
Bradykinin Antagonists ◽  
Transient Receptor

Object The authors previously discovered that genes for the bradykinin-1 (B1) receptor and the transient receptor potential vanilloid subtype 1 (TRPV1) were overexpressed in animals exhibiting thermal hyperalgesia (TH) following spinal cord injury (SCI). They now report the effect of TRPV1 (AMG9810) and B1 (Lys-[Des-Arg9, Leu8]-bradykinin) antagonists on TH in animals following SCI. Methods The rats were subjected to contusion SCI and then divided into groups in which TH did or did not develop. The animals from both groups were given either AMG9810, Lys-(Des-Arg9, Leu8)-bradykinin, or the drug-specific vehicle (control groups). Animals were tested for TH preinjury and at regular intervals after SCI by using the hindlimb withdrawal latency test. Conclusions The administration of AMG9810 likely improves TH as a result of a generalized analgesic effect, whereas the effect of Lys-(Des-Arg9, Leu8)-bradykinin appears more specific to the reversal of TH. This information has potential usefulness in the development of treatment strategies for post-SCI neuropathic pain.

The Role of The TRPV1 Endogenous Agonist N-Oleoyldopamine in Modulation of Nociceptive Signaling at the Spinal Cord Level

2009 ◽  
Vol 102 (1) ◽  
pp. 234-243 ◽  
Author(s):  
Diana Spicarova ◽  
Jiri Palecek
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Spinal Cord Dorsal Horn ◽  
Transient Receptor Potential Vanilloid ◽  
High Concentration ◽  
Low Concentration ◽  
Trpv1 Receptors ◽  
Mepsc Frequency

Transient receptor potential vanilloid (TRPV1) receptors are abundant in a subpopulation of primary sensory neurons that convey nociceptive information from the periphery to the spinal cord dorsal horn. The TRPV1 receptors are expressed on both the peripheral and central branches of these dorsal root ganglion (DRG) neurons and can be activated by capsaicin, heat, low pH, and also by recently described endogenous lipids. Using patch-clamp recordings from superficial dorsal horn (DH) neurons in acute spinal cord slices, the effect of application of the endogenous TRPV1 agonist N-oleoyldopamine (OLDA) on the frequency of miniature excitatory postsynaptic currents (mEPSCs) was evaluated. A high concentration OLDA (10 μM) solution was needed to increase the mEPSC frequency, whereas low concentration OLDA (0.2 μM) did not evoke any change under control conditions. The increase was blocked by the TRPV1 antagonists SB366791 or BCTC. Application of a low concentration of OLDA evoked an increase in mEPSC frequency after activation of protein kinase C by phorbol ester (PMA) and bradykinin or in slices from animals with peripheral inflammation. Increasing the bath temperature from 24 to 34°C enhanced the basal mEPSC frequency, but the magnitude of changes in the mEPSC frequency induced by OLDA administration was similar at both temperatures. Our results suggest that presumed endogenous agonists of TRPV1 receptors, like OLDA, could have a considerable impact on synaptic transmission in the spinal cord, especially when TRPV1 receptors are sensitized. Spinal TRPV1 receptors could play a pivotal role in modulation of nociceptive signaling in inflammatory pain.

scholarly journals Paclitaxel Induces Upregulation of Transient Receptor Potential Vanilloid 1 Expression in the Rat Spinal Cord

2020 ◽  
Vol 21 (12) ◽  
pp. 4341 ◽  
Author(s):  
Yukako Kamata ◽  
Toshie Kambe ◽  
Terumasa Chiba ◽  
Ken Yamamoto ◽  
Kazuyoshi Kawakami ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Mechanical Allodynia ◽  
Transient Receptor Potential ◽  
Thermal Hyperalgesia ◽  
Receptor Potential ◽  
Intrathecal Administration ◽  
Transient Receptor Potential Vanilloid ◽  
Rat Spinal Cord ◽  
Trpv1 Receptor ◽  
Transient Receptor

Painful peripheral neuropathy is a common adverse effect of paclitaxel (PTX) treatment. To analyze the contribution of transient receptor potential vanilloid 1 (TRPV1) in the development of PTX-induced mechanical allodynia/hyperalgesia and thermal hyperalgesia, TRPV1 expression in the rat spinal cord was analyzed after intraperitoneal administration of 2 and 4 mg/kg PTX. PTX treatment increased the expression of TRPV1 protein in the spinal cord. Immunohistochemistry showed that PTX (4 mg/kg) treatment increased TRPV1 protein expression in the superficial layers of the spinal dorsal horn 14 days after treatment. Behavioral assessment using the paw withdrawal response showed that PTX-induced mechanical allodynia/hyperalgesia and thermal hyperalgesia after 14 days was significantly inhibited by oral or intrathecal administration of the TRPV1 antagonist AMG9810. We found that intrathecal administration of small interfering RNA (siRNA) to knock down TRPV1 protein expression in the spinal cord significantly decreased PTX-induced mechanical allodynia/hyperalgesia and thermal hyperalgesia. Together, these results demonstrate that TRPV1 receptor expression in spinal cord contributes, at least in part, to the development of PTX-induced painful peripheral neuropathy. TRPV1 receptor antagonists may be useful in the prevention and treatment of PTX-induced peripheral neuropathic pain.

scholarly journals Histamine induces peripheral and central hypersensitivity to bladder distension via the histamine H1 receptor and TRPV1

2020 ◽  
Vol 318 (2) ◽  
pp. F298-F314 ◽  
Author(s):  
Luke Grundy ◽  
Ashlee Caldwell ◽  
Sonia Garcia Caraballo ◽  
Andelain Erickson ◽  
Gudrun Schober ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Transient Receptor Potential ◽  
Ex Vivo ◽  
Transient Receptor Potential Vanilloid ◽  
Receptor Subtypes ◽  
Urothelial Cells ◽  
Bladder Pain ◽  
Bladder Distension ◽  
Bladder Afferents

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a common chronic pelvic disorder with sensory symptoms of urinary urgency, frequency, and pain, indicating a key role for hypersensitivity of bladder-innervating sensory neurons. The inflammatory mast cell mediator histamine has long been implicated in IC/BPS, yet the direct interactions between histamine and bladder afferents remain unclear. In the present study, we show, using a mouse ex vivo bladder afferent preparation, that intravesical histamine enhanced the mechanosensitivity of subpopulations of afferents to bladder distension. Histamine also recruited “silent afferents” that were previously unresponsive to bladder distension. Furthermore, in vivo intravesical histamine enhanced activation of dorsal horn neurons within the lumbosacral spinal cord, indicating increased afferent signaling in the central nervous system. Quantitative RT-PCR revealed significant expression of histamine receptor subtypes ( Hrh1– Hrh3) in mouse lumbosacral dorsal root ganglia (DRG), bladder detrusor smooth muscle, mucosa, and isolated urothelial cells. In DRG, Hrh1 was the most abundantly expressed. Acute histamine exposure evoked Ca2+ influx in select populations of DRG neurons but did not elicit calcium transients in isolated primary urothelial cells. Histamine-induced mechanical hypersensitivity ex vivo was abolished in the presence of the histamine H1 receptor antagonist pyrilamine and was not present in preparations from mice lacking transient receptor potential vanilloid 1 (TRPV1). Together, these results indicate that histamine enhances the sensitivity of bladder afferents to distension via interactions with histamine H1 receptor and TRPV1. This hypersensitivity translates to increased sensory input and activation in the spinal cord, which may underlie the symptoms of bladder hypersensitivity and pain experienced in IC/BPS.

Sign in / Sign up

Export Citation Format

Share Document