1
|
Cairns BE, He N. β 2-adrenergic receptor activation decreases the mechanical sensitivity of rat masticatory muscle afferent fibres. J Oral Rehabil 2024. [PMID: 38894554 DOI: 10.1111/joor.13787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/29/2024] [Accepted: 06/10/2024] [Indexed: 06/21/2024]
Abstract
BACKGROUND Activation of β2 adrenergic receptors reduces cutaneous mechanical pain thresholds in rats. While β2 adrenergic receptor activation may contribute to mechanisms that underlie temporomandibular joint pain, its effect on masticatory muscle pain sensitivity is uncertain. OBJECTIVES The current study sought to determine the extent to which β adrenergic receptors are expressed by masticatory muscle afferent fibres, and to assess the effect of local activation of these receptors on the mechanical sensitivity of masticatory muscle afferent fibres in rats. METHODS Trigeminal ganglion neurons that innervate the rat (n = 12) masseter muscle and lower lip were identified by tissue injection of fluorescent dyes and were then stained with antibodies against β1 or β2 adrenergic receptors. Extracellular recordings from 60 trigeminal ganglion neurons that innervate the masticatory muscle were undertaken in a second group of anaesthetised rats of both sexes (n = 37) to assess afferent mechanical activation thresholds. Thresholds were assessed before and after injection of the β adrenergic receptor agonists into masticatory muscle. RESULTS β1 and β2 adrenergic receptor expression was greater in labial skin than in masticatory muscle ganglion neurons (p < .05, one-way ANOVA, Holm-Sidak test). There was a higher expression of β2 adrenergic receptors in masticatory muscle ganglion neurons in males than in females. The mixed β agonist isoproterenol increased afferent mechanical activation threshold in male but not female rats (p < .05, Mann-Whitney test). In male rats, salbutamol, a β2 selective agonist, also increased afferent mechanical activation threshold but hydralazine, a vasodilator, did not (p < .05, Mann-Whitney test). CONCLUSION Activation of β2 adrenergic receptors decreases the mechanical sensitivity of masticatory muscle afferent fibres in a sex-related manner.
Collapse
Affiliation(s)
- Brian E Cairns
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Nathan He
- Department of Anesthesia, Pharmacology and Therapeutics, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
2
|
Hong K. Classification of emotional stress and physical stress using a multispectral based deep feature extraction model. Sci Rep 2023; 13:2693. [PMID: 36792679 PMCID: PMC9931761 DOI: 10.1038/s41598-023-29903-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
A classification model (Stress Classification-Net) of emotional stress and physical stress is proposed, which can extract classification features based on multispectral and tissue blood oxygen saturation (StO2) characteristics. Related features are extracted on this basis, and the learning model with frequency domain and signal amplification is proposed for the first time. Given that multispectral imaging signals are time series data, time series StO2 is extracted from spectral signals. The proper region of interest (ROI) is obtained by a composite criterion, and the ROI source is determined by the universality and robustness of the signal. The frequency-domain signals of ROI are further obtained by wavelet transform. To fully utilize the frequency-domain characteristics, the multi-neighbor vector of locally aggregated descriptors (MN-VLAD) model is proposed to extract useful features. The acquired time series features are finally put into the long short-term memory (LSTM) model to learn the classification characteristics. Through SC-NET model, the classification signals of emotional stress and physical stress are successfully obtained. Experiments show that the classification result is encouraging, and the accuracy of the proposed algorithm is over 90%.
Collapse
Affiliation(s)
- Kan Hong
- Jiangxi University of Finance and Economics, Nanchang, China.
| |
Collapse
|
3
|
Differences in the regulatory mechanism of blood flow in the orofacial area mediated by neural and humoral systems. J Comp Physiol B 2023; 193:109-124. [PMID: 36436073 DOI: 10.1007/s00360-022-01470-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 11/09/2022] [Accepted: 11/16/2022] [Indexed: 11/29/2022]
Abstract
Marked blood flow (BF) changes mediated by the autonomic neural and humoral systems may be important for orofacial hemodynamics and functions. However, it remains questionable whether differences in the autonomic vasomotor responses mediated by neural and humoral systems exist in the orofacial area. This study examined whether there are differences in changes in the BF and vascular conductance (VC) between the masseter muscle and lower lip mediated by autonomic neural and humoral systems in urethane-anesthetized rats. Electrical stimulation of the central cut end of the lingual nerve elicited BF increases in the masseter (mainly cholinergic) and lower lip (mainly non-cholinergic), accompanied by an increase in arterial blood pressure (ABP), while cervical sympathetic trunk stimulation consistently decreased BF at both sites. The lingual nerve stimulation induced a biphasic change in the VC in the masseter, consisting of an initial decrease and a successive increase. This decrease in VC was positively correlated with changes in ABP and diminished by guanethidine. Cervical vagus nerve stimulation also induced BF increases at both sites; the increases were greater in the masseter than in the lower lip. Adrenal nerve stimulation and isoproterenol administration induced BF increases in the masseter but not in the lower lip. These results indicate that cholinergic parasympathetic-mediated hemodynamics evoked by trigeminal somatosensory inputs are closely related to ABP changes. The sympathetic nervous system, including the sympathoadrenal system and visceral inputs, may be more involved in hemodynamics in the muscles than in epithelial tissues in the orofacial area.
Collapse
|
4
|
Cairns BE. The contribution of autonomic mechanisms to pain in temporomandibular disorders: A narrative review. J Oral Rehabil 2022; 49:1115-1126. [PMID: 36098708 DOI: 10.1111/joor.13370] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/22/2022] [Accepted: 09/06/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Temporomandibular disorders (TMD) are diagnosed based on symptom presentation and, like other functional pain disorders, often lack definitive pathology. There is a strong association between elevated stress levels and the severity of TMD-related pain, which suggests that alterations in autonomic tone may contribute to this pain condition. OBJECTIVES This narrative review examines the association between altered autonomic function and pain in TMD. METHODS Relevant articles were identified by searching PubMed and through the reference list of those studies. RESULTS TMD sufferers report an increased incidence of orthostatic hypotension. As in other chronic musculoskeletal pain conditions, TMD is associated with increased sympathetic tone, diminished baroreceptor reflex sensitivity and decreased parasympathetic tone. It remains to be determined whether ongoing pain drives these autonomic changes and/or is exacerbated by them. To examine whether increased sympathetic tone contributes to TMD-related pain through β2 adrenergic receptor activation, clinical trials with the beta blocker propranolol have been undertaken. Although evidence from small studies suggested propranolol reduced TMD-related pain, a larger clinical trial did not find a significant effect of propranolol treatment. This is consistent with human experimental pain studies that were unable to demonstrate an effect of β2 adrenergic receptor activation or inhibition on masticatory muscle pain. In preclinical models of temporomandibular joint arthritis, β2 adrenergic receptor activation appears to contribute to inflammation and nociception, whereas in masticatory muscle, α1 adrenergic receptor activation has been found to induce mechanical sensitization. Some agents used to treat TMD, such as botulinum neurotoxin A, antidepressants and α2 adrenergic receptor agonists, may interact with the autonomic nervous system as part of their analgesic mechanism. CONCLUSION Even if dysautonomia turns out to be a consequence rather than a causative factor of painful TMD, the study of its role has opened up a greater understanding of the pathogenesis of this condition.
Collapse
Affiliation(s)
- Brian E Cairns
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| |
Collapse
|
5
|
Bordignon NAF, Regalo S, de Vasconcelos PB, Prandi MVR, Hotta TH, Gonçalves LMN, Regalo IH, Siéssere S, Palinkas M. Impact of chronic allergic rhinitis on bite force and electromyographic activity of masseter and temporalis muscles of adult women. J Clin Exp Dent 2020; 12:e488-e493. [PMID: 32509232 PMCID: PMC7263770 DOI: 10.4317/jced.56660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 02/24/2020] [Indexed: 12/29/2022] Open
Abstract
Background The aim of this study was to analyse the stomatognathic system of adult women with chronic allergic rhinitis by means of molar bite force and electromyographic activity of the masseter and temporalis muscles.
Material and Methods A total of 26 subjects were screened and divided into two distinct groups: chronic allergic rhinitis group (n = 13) and healthy control group (n = 13). Subjects were assessed by maximal molar bite force (right and left) and normalized electromyographic activity of mandibular tasks (rest, right and left laterality, protrusion and maximal voluntary contraction). Data were submitted to Student’s t test (p< .05).
Results There was significant difference in right (p = .03) and left (p = .04) maximal molar bite force with force reduction in the chronic allergic rhinitis group. There was significant difference in normalized electromyographic activity in maximal voluntary contraction in the right (p =.01) and left (p = .01) temporalis muscles, with increased electromyographic activity in the masticatory muscles for the chronic allergic rhinitis group. Conclusions The results suggest that chronic allergic rhinitis in adult women promoted negative changes in the electromyographic activity of temporalis muscles in maximal voluntary contraction and maximal molar bite force. Key words:Rhinitis, occlusal force, electromyography, masticatory muscles.
Collapse
Affiliation(s)
| | - Simone Regalo
- DDS, PhD, Professor. Department of Basic and Oral Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo; National Institute and Technology - Translational Medicine (INCT.TM), São Paulo, Brazil
| | - Paulo-Batista de Vasconcelos
- MS. Department of Basic and Oral Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| | | | - Takami-Hirono Hotta
- DDS, Professor. Department of Dental Materials and Prosthodontic, Ribeirão Preto School of Dentistry, University of São Paulo, Brazil
| | - Ligia-Maria-Napolitano Gonçalves
- DDS, PhD, Professor. Department of Basic and Oral Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo; Brazil
| | - Isabela-Hallak Regalo
- MS. Department of Basic and Oral Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| | - Selma Siéssere
- DDS, PhD, Professor. Department of Basic and Oral Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo; National Institute and Technology - Translational Medicine (INCT.TM), São Paulo, Brazil
| | - Marcelo Palinkas
- DDS, PhD, Professor. Department of Basic and Oral Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo; Faculty Anhanguera, Ribeirão Preto and National Institute and Technology - Translational Medicine (INCT.TM), São Paulo, Brazil
| |
Collapse
|
6
|
Ito A, Ohnuki Y, Suita K, Ishikawa M, Mototani Y, Shiozawa K, Kawamura N, Yagisawa Y, Nariyama M, Umeki D, Nakamura Y, Okumura S. Role of β-adrenergic signaling in masseter muscle. PLoS One 2019; 14:e0215539. [PMID: 30986276 PMCID: PMC6464212 DOI: 10.1371/journal.pone.0215539] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 04/03/2019] [Indexed: 02/07/2023] Open
Abstract
In skeletal muscle, the major isoform of β-adrenergic receptor (β-AR) is β2-AR and the minor isoform is β1-AR, which is opposite to the situation in cardiac muscle. Despite extensive studies in cardiac muscle, the physiological roles of the β-AR subtypes in skeletal muscle are not fully understood. Therefore, in this work, we compared the effects of chronic β1- or β2-AR activation with a specific β1-AR agonist, dobutamine (DOB), or a specific β2-AR agonist, clenbuterol (CB), on masseter and cardiac muscles in mice. In cardiac muscle, chronic β1-AR stimulation induced cardiac hypertrophy, fibrosis and myocyte apoptosis, whereas chronic β2-AR stimulation induced cardiac hypertrophy without histological abnormalities. In masseter muscle, however, chronic β1-AR stimulation did not induce muscle hypertrophy, but did induce fibrosis and apoptosis concomitantly with increased levels of p44/42 MAPK (ERK1/2) (Thr-202/Tyr-204), calmodulin kinase II (Thr-286) and mammalian target of rapamycin (mTOR) (Ser-2481) phosphorylation. On the other hand, chronic β2-AR stimulation in masseter muscle induced muscle hypertrophy without histological abnormalities, as in the case of cardiac muscle, concomitantly with phosphorylation of Akt (Ser-473) and mTOR (Ser-2448) and increased expression of microtubule-associated protein light chain 3-II, an autophagosome marker. These results suggest that the β1-AR pathway is deleterious and the β2-AR is protective in masseter muscle. These data should be helpful in developing pharmacological approaches for the treatment of skeletal muscle wasting and weakness.
Collapse
Affiliation(s)
- Aiko Ito
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
- Department of Orthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yoshiki Ohnuki
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Kenji Suita
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Misao Ishikawa
- Department of Oral Anatomy, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yasumasa Mototani
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Kouichi Shiozawa
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Naoya Kawamura
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
- Department of Periodontology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yuka Yagisawa
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
- Department of Orthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Megumi Nariyama
- Department of Pediatric Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Daisuke Umeki
- Department of Orthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yoshiki Nakamura
- Department of Orthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Satoshi Okumura
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
- * E-mail:
| |
Collapse
|
7
|
|
8
|
Interactions between β-adrenergic vasodilation and cervical sympathetic nerves are mediated by α 2-adrenoceptors in the rat masseter muscle. J Physiol Sci 2016; 67:699-709. [PMID: 27826897 PMCID: PMC5910521 DOI: 10.1007/s12576-016-0499-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 10/25/2016] [Indexed: 11/24/2022]
Abstract
Neural and humoral autonomic mechanisms may be important in the maintenance of blood flow in the masseter muscle (MBF). However, their interactions remain unclear. In this study, we examined interactions between neural and humoral regulation of MBF and investigated the mechanisms mediating these interactions in urethane-anesthetized rats. Stimulation of the adrenal nerve (AN) projecting to the adrenal medulla increased MBF, and this increase was mediated by β-adrenoceptors. Sectioning of the superior cervical sympathetic trunk (CST) significantly inhibited increases in MBF induced by AN stimulation during high activity in the CST, but not during low activity. AN stimulation with clonidine after CST sectioning induced a significant increased in MBF, however phenylephrine had no observable effect. Pretreatment with yohimbine or propranolol significantly inhibited the increase in the MBF. Our results suggest an interaction between β-adrenergic vasodilation evoked by circulating adrenaline and the cervical sympathetic nerves that is mediated by α2-adrenoceptors in the masseter muscle.
Collapse
|
9
|
Wong WY, Ward LC, Fong CW, Yap WN, Brown L. Anti-inflammatory γ- and δ-tocotrienols improve cardiovascular, liver and metabolic function in diet-induced obese rats. Eur J Nutr 2015; 56:133-150. [PMID: 26446095 DOI: 10.1007/s00394-015-1064-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 09/25/2015] [Indexed: 12/26/2022]
Abstract
PURPOSE This study tested the hypothesis that γ- and δ-tocotrienols are more effective than α-tocotrienol and α-tocopherol in attenuating the signs of diet-induced metabolic syndrome in rats. METHODS Five groups of rats were fed a corn starch-rich (C) diet containing 68 % carbohydrates as polysaccharides, while the other five groups were fed a diet (H) high in simple carbohydrates (fructose and sucrose in food, 25 % fructose in drinking water, total 68 %) and fats (beef tallow, total 24 %) for 16 weeks. Separate groups from each diet were supplemented with either α-, γ-, δ-tocotrienol or α-tocopherol (85 mg/kg/day) for the final 8 of the 16 weeks. RESULTS H rats developed visceral obesity, hypertension, insulin resistance, cardiovascular remodelling and fatty liver. α-Tocopherol, α-, γ- and δ-tocotrienols reduced collagen deposition and inflammatory cell infiltration in the heart. Only γ- and δ-tocotrienols improved cardiovascular function and normalised systolic blood pressure compared to H rats. Further, δ-tocotrienol improved glucose tolerance, insulin sensitivity, lipid profile and abdominal adiposity. In the liver, these interventions reduced lipid accumulation, inflammatory infiltrates and plasma liver enzyme activities. Tocotrienols were measured in heart, liver and adipose tissue showing that chronic oral dosage delivered tocotrienols to these organs despite low or no detection of tocotrienols in plasma. CONCLUSION In rats, δ-tocotrienol improved inflammation, heart structure and function, and liver structure and function, while γ-tocotrienol produced more modest improvements, with minimal changes with α-tocotrienol and α-tocopherol. The most important mechanism of action is likely to be reduction in organ inflammation.
Collapse
Affiliation(s)
- Weng-Yew Wong
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, 4072, Australia
- Laboratory of Cardiovascular Signalling, Centenary Institute, Sydney, NSW, 2050, Australia
| | - Leigh C Ward
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, 4072, Australia
| | - Chee Wai Fong
- Davos Life Science Pte Ltd, 3 Biopolis Drive, #04-19 Synapse, Singapore, 138623, Singapore
| | - Wei Ney Yap
- Davos Life Science Pte Ltd, 3 Biopolis Drive, #04-19 Synapse, Singapore, 138623, Singapore
| | - Lindsay Brown
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, QLD, 4350, Australia.
| |
Collapse
|
10
|
Abstract
BACKGROUND Epinephrine was recently shown to induce a hypotension episode. Activation of β₂-adrenoceptors with smooth muscle relaxation may be the underlying mechanism. This study investigated the effects of ICI 118551, a β₂-adrenoceptors antagonist, on epinephrine-induced blood pressure reduction via different administration routes in rats. METHODS A total of 144 Sprague Dawley rats were equally randomized into 3 groups (intranasal, intravenous, and intra-arterial administration), each with 4 subgroups: saline + saline, ICI 118551 + saline, saline + epinephrine, and ICI 118551 + epinephrine. All rats were anesthetized while spontaneously breathing. Epinephrine was administered at doses of 5 μg/kg via nose, 0.25 μg/kg via femoral vein, and 0.1 μg/kg via aorta. Mean arterial pressure and heart rate were monitored. RESULTS Mean arterial pressure decreased in all 3 saline + epinephrine subgroups after administration (P < 0.05), whereas it did not in other subgroups. Heart rate had no significant change in all subgroups. CONCLUSIONS Epinephrine-induced blood pressure reduction can be prevented by ICI 118551 in rats, suggesting that the activation of β₂-adrenoceptors contributes to blood pressure reduction.
Collapse
|
11
|
Parasympathetic reflex vasodilation in the cerebral hemodynamics of rats. J Comp Physiol B 2014; 184:385-99. [PMID: 24504265 DOI: 10.1007/s00360-014-0807-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 01/16/2014] [Accepted: 01/21/2014] [Indexed: 10/25/2022]
Abstract
We investigated the role of parasympathetic reflex vasodilation in the regulation of the cerebral hemodynamics, and whether GABAA receptors modulate the response. We examined the effects of activation of the parasympathetic fibers through trigeminal afferent inputs on blood flow in the internal carotid artery (ICABF) and the cerebral blood vessels (rCBF) in parietal cortex in urethane-anesthetized rats. Electrical stimulation of the central cut end of the lingual nerve (LN) elicited intensity- and frequency-dependent increases in ICABF that were independent of changes in external carotid artery blood flow. Increases in ICABF were elicited by LN stimulation regardless of the presence or absence of sympathetic innervation. The ICABF increases evoked by LN stimulation were almost abolished by the intravenous administration of hexamethonium (10 mg kg(-1)) and were reduced significantly by atropine administration (0.1 mg kg(-1)). Although the LN stimulation alone had no significant effect on rCBF, LN stimulation in combination with a blocker of the GABAA receptor pentylenetetrazole increased the rCBF markedly. This increase in rCBF was reduced significantly by the administration of hexamethonium and atropine. These observations indicate that the increases in both ICABF and rCBF are evoked by parasympathetic activation via the trigeminal-mediated reflex. The rCBF increase evoked by LN stimulation is thought to be limited by the GABAA receptors in the central nervous system. These results suggest that the parasympathetic reflex vasodilation and its modulation mediated by GABA receptors within synaptic transmission in the brainstem are involved in the regulation of the cerebral hemodynamics during trigeminal afferent inputs.
Collapse
|
12
|
Ishii H, Izumi H. GABAB receptors in the NTS mediate the inhibitory effect of trigeminal nociceptive inputs on parasympathetic reflex vasodilation in the rat masseter muscle. Am J Physiol Regul Integr Comp Physiol 2012; 302:R776-84. [DOI: 10.1152/ajpregu.00569.2011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study was designed to examine whether trigeminal nociceptive inputs are involved in the modulation of parasympathetic reflex vasodilation in the jaw muscles. This was accomplished by investigating the effects of noxious stimulation to the orofacial area with capsaicin, and by microinjecting GABAA and GABAB receptor agonists or antagonists into the nucleus of the solitary tract (NTS), on masseter hemodynamics in urethane-anesthetized rats. Electrical stimulation of the central cut end of the cervical vagus nerve (cVN) in sympathectomized animals bilaterally increased blood flow in the masseter muscle (MBF). Increases in MBF evoked by cVN stimulation were markedly reduced following injection of capsaicin into the anterior tongue in the distribution of the lingual nerve or lower lip, but not when injected into the skin of the dorsum of the foot. Intravenous administration of either phentolamine or propranolol had no effect on the inhibitory effects of capsaicin injection on the increases of MBF evoked by cVN stimulation, which were largely abolished by microinjecting the GABAB receptor agonist baclofen into the NTS. Microinjection of the GABAB receptor antagonist CGP-35348 into the NTS markedly attenuated the capsaicin-induced inhibition of MBF increase evoked by cVN stimulation, while microinjection of the GABAA receptor antagonist bicuculline did not. Our results indicate that trigeminal nociceptive inputs inhibit vagal-parasympathetic reflex vasodilation in the masseter muscle and suggest that the activation of GABAB rather than GABAA receptors underlies the observed inhibition in the NTS.
Collapse
Affiliation(s)
- Hisayoshi Ishii
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Hiroshi Izumi
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| |
Collapse
|
13
|
Bereiter DA, Okamoto K. Neurobiology of estrogen status in deep craniofacial pain. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011; 97:251-84. [PMID: 21708314 DOI: 10.1016/b978-0-12-385198-7.00010-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pain in the temporomandibular joint (TMJ) region often occurs with no overt signs of injury or inflammation. Although the etiology of TMJ-related pain may involve multiple factors, one likely risk factor is female gender or estrogen status. Evidence is reviewed from human and animal studies, supporting the proposition that estrogen status acts peripherally or centrally to influence TMJ nociceptive processing. A new model termed the "TMJ pain matrix" is proposed as critical for the initial integration of TMJ-related sensory signals in the lower brainstem that is both modified by estrogen status, and closely linked to endogenous pain and autonomic control pathways.
Collapse
Affiliation(s)
- David A Bereiter
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, MN 55455, USA
| | | |
Collapse
|
14
|
Zhang W, Shibamoto T, Kurata Y, Kohno H. Effects of β-adrenoceptor antagonists on anaphylactic hypotension in conscious rats. Eur J Pharmacol 2010; 650:303-8. [PMID: 20959119 DOI: 10.1016/j.ejphar.2010.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 09/29/2010] [Accepted: 10/06/2010] [Indexed: 11/16/2022]
Abstract
Anaphylactic shock is sometimes fatal or resistant to therapy in patients treated with propranolol, a nonselective β-adrenoceptor antagonist, against cardiovascular diseases. However, it remains unknown which subtype of β-adrenoceptors, β(1)- or β(2)-adrenoceptor, is primarily responsible for the detrimental effects of propranolol on anaphylactic hypotension. Effects of β(1)- and β(2)-adrenoceptor antagonists were therefore determined on the survival rate and systemic hypotension in conscious Sprague-Dawley rats that suffered from anaphylactic shock. Mean arterial pressure and portal venous pressure were simultaneously measured. The control rats showed a decrease in mean arterial pressure and an increase in portal venous pressure, but did not die within 48h after an injection of ovalbumin antigen. The survival rate of the rats pretreated with propranolol (1mg/kg; n=7), the selective β(2)-adrenoceptor antagonist ICI 118,551 (0.5mg/kg; n=7), or adrenalectomy (n=7) was significantly smaller than that with the selective β(1)-adrenoceptor antagonist atenolol (2mg/kg; n=7). However, the changes in mean arterial pressure and portal venous pressure were similar for 10min after antigen among any groups, although propranolol and atenolol attenuated the antigen-induced increase in heart rate. Furthermore, bolus injections of epinephrine (3μg/kg) at 3 and 5min after antigen prevented the death of the atenolol-pretreated rats, but only marginally prolonged the survival rates for the ICI 118,551- or propranolol-pretreated and adrenalectomized rats. In conclusion, in rat anaphylactic shock, inhibition of β(2)-adrenoceptor causes more detrimental effects than that of the β(1)-adrenoceptor. These β-adrenoceptor antagonists may exert detrimental effects on rat systemic anaphylaxis via inhibiting beneficial actions of catecholamines endogenously released from the adrenal gland.
Collapse
Affiliation(s)
- Wei Zhang
- Department of Physiology II, Kanazawa Medical University, Uchinada Ishikawa 920-0293, Japan
| | | | | | | |
Collapse
|
15
|
Vagal visceral inputs to the nucleus of the solitary tract: Involvement in a parasympathetic reflex vasodilator pathway in the rat masseter muscle. Brain Res 2010; 1312:41-53. [DOI: 10.1016/j.brainres.2009.11.073] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 11/25/2009] [Accepted: 11/25/2009] [Indexed: 11/17/2022]
|
16
|
Sudo E, Ishii H, Niioka T, Hirai T, Izumi H. Parasympathetic vasodilator fibers in rat digastric muscle. Brain Res 2009; 1302:125-31. [DOI: 10.1016/j.brainres.2009.09.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 09/02/2009] [Accepted: 09/09/2009] [Indexed: 11/29/2022]
|