1
|
Okada Y, Sato T, Islam ST, Ohke H, Saitoh M, Ishii H. Site-specific autonomic vasomotor responses and their interactions in rat gingiva. Microvasc Res 2024; 152:104646. [PMID: 38092222 DOI: 10.1016/j.mvr.2023.104646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/06/2023] [Accepted: 12/08/2023] [Indexed: 12/17/2023]
Abstract
Blood flow in the gingiva, comprising the interdental papilla as well as attached and marginal gingiva, is important for maintaining of gingival function and is modulated by risk factors such as stress that may lead to periodontal disease. Marked blood flow changes mediated by the autonomic (parasympathetic and sympathetic) nervous system may be essential for gingival hemodynamics. However, differences in autonomic vasomotor responses and their functional significance in different parts of the gingiva are unclear. We examined the differences in autonomic vasomotor responses and their interactions in the gingiva of anesthetized rats. Parasympathetic vasodilation evoked by the trigeminal (lingual nerve)-mediated reflex elicited frequency-dependent blood flow increases in gingivae, with the increases being greatest in the interdental papilla. Parasympathetic blood flow increases were significantly reduced by intravenous administration of the atropine and VIP antagonist. The blood flow increase evoked by acetylcholine administration was higher in the interdental papilla than in the attached gingiva, whereas that evoked by VIP agonist administration was greater in the attached gingiva than in the interdental papilla. Activation of the cervical sympathetic nerves decreased gingival blood flow and inhibited parasympathetically induced blood flow increases. Our results suggest that trigeminal-parasympathetic reflex vasodilation 1) is more involved in the regulation of blood flow in the interdental papilla than in the other parts of the gingiva, 2) is mediated by cholinergic (interdental papilla) and VIPergic systems (attached gingiva), and 3) is inhibited by excess sympathetic activity. These results suggest a role in the etiology of periodontal diseases during mental stress.
Collapse
Affiliation(s)
- Yunosuke Okada
- Division of Pediatric Dentistry, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Toshiya Sato
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Syed Taufiqul Islam
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Hanako Ohke
- Division of Dental Anesthesiology, Department of Human Biology and Pathophysiology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Masato Saitoh
- Division of Pediatric Dentistry, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Hisayoshi Ishii
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan.
| |
Collapse
|
2
|
Chronic Cannabis Intoxication and Propofol-Induced Salivation: Causes and Considerations. PATHOPHYSIOLOGY 2022; 29:223-232. [PMID: 35736646 PMCID: PMC9229402 DOI: 10.3390/pathophysiology29020018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 11/16/2022] Open
Abstract
Legalization/decriminalization of cannabis will increase the numbers of patients who have had recent exposure to recreational or medical cannabis. Currently, little has been reported about potential interactions between cannabis use and Propofol anesthesia e.g., for oropharyngeal procedures. We describe three cases of ‘cannabis-induced hypersalivation after propofol’ (CHAP) and present our institutions’ experience with this unique pharmacological combination. Increased hypersalivation may complicate procedures and represent a procedural risk of suffocation. We evaluate possible pharmacological interactions that might underlie this phenomenon and consider management options going forward.
Collapse
|
3
|
Sato T, Mito K, Ishii H. Relationship between impaired parasympathetic vasodilation and hyposalivation in parotid glands associated with type 2 diabetes mellitus. Am J Physiol Regul Integr Comp Physiol 2020; 318:R940-R949. [PMID: 32209022 DOI: 10.1152/ajpregu.00016.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the relationship between hemodynamics in the three major salivary glands and salivary secretion in urethane-anesthetized and sympathectomized type 2 diabetic and nondiabetic rats via laser speckle imaging and by collecting the saliva. Lingual nerve stimulation elicited rapid increases in glandular blood flow and induced salivary secretion from the three glands in both diabetic and nondiabetic rats. In the parotid gland, the magnitude of blood flow increase and salivary secretion was significantly lower in the diabetic rats when compared with the nondiabetic rats; however, this was not observed in the other glands. Although the intravenous administration of acetylcholine increased blood flow in the parotid gland in a dose-dependent manner, the response was significantly lower in the diabetic rats when compared with the nondiabetic rats. Similarly, mRNA expression levels of M1 and M3 muscarinic acetylcholine receptors in the parotid gland were relatively lower in the diabetic rats compared with the nondiabetic rats. Our results indicate that type 2 diabetes impairs parasympathetic vasodilation and salivary secretion in the parotid gland and suggest that disturbances in the cholinergic vasodilator pathway may contribute to the underlying mechanisms involved in the disruption of parasympathetic nerve-mediated glandular vasodilation.
Collapse
Affiliation(s)
- Toshiya Sato
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Kohei Mito
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Hisayoshi Ishii
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| |
Collapse
|
4
|
Ohke H, Sato T, Mito K, Terumitsu M, Ishii H. Effect of the parasympathetic vasodilation on temperature regulation via trigeminal afferents in the orofacial area. J Physiol Sci 2020; 70:22. [PMID: 32234014 PMCID: PMC7109144 DOI: 10.1186/s12576-020-00749-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 03/20/2020] [Indexed: 02/03/2023]
Abstract
The skin temperature (Tm) of the orofacial area influences orofacial functions and is related to the blood flow (BF). Marked increases in BF mediated by parasympathetic vasodilation may be important for orofacial Tm regulation. Therefore, we examined the relationship between parasympathetic reflex vasodilation and orofacial Tm in anesthetized rats. Electrical stimulation of the central cut end of the lingual nerve (LN) elicited significant increases in BF and Tm in the lower lip. These increases were significantly reduced by hexamethonium, but not atropine. VIP agonist increased both BF and Tm in the lower lip. The activation of the superior cervical sympathetic trunk (CST) decreased BF and Tm in the lower lip; however, these decreases were significantly inhibited by LN stimulation. Our results suggest that parasympathetic vasodilation plays an important role in the maintaining the hemodynamics and Tm in the orofacial area, and that VIP may be involved in this response.
Collapse
Affiliation(s)
- Hanako Ohke
- Division of Dental Anesthesiology, Department of Human Biology and Pathophysiology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Toshiya Sato
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan
| | - Kohei Mito
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan
| | - Makoto Terumitsu
- Division of Dental Anesthesiology, Department of Human Biology and Pathophysiology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Hisayoshi Ishii
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan.
| |
Collapse
|
5
|
Nezu A, Morita T, Nagai T, Tanimura A. Simultaneous monitoring of Ca 2+ responses and salivary secretion in live animals reveals a threshold intracellular Ca 2+ concentration for salivation. Exp Physiol 2018; 104:61-69. [PMID: 30367746 DOI: 10.1113/ep086868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Accepted: 10/25/2018] [Indexed: 12/21/2022]
Abstract
NEW FINDINGS What is the central question of this study? The effects of Ca2+ responses on salivary fluid secretion have been studied indirectly by monitoring ion channel activities and other indices. Therefore, Ca2+ responses during salivary secretion remain poorly understood. What is the main finding and its importance? Herein, we developed a simultaneous monitoring system for Ca2+ responses and salivary secretion in live animals using a YC-Nano50-expressing submandibular gland and a fibre-optic pressure sensor. This new approach revealed a clear time lag between the onset of Ca2+ responses and salivary secretion. We also estimated the [Ca2+ ]i and provided direct evidence for the regulation of salivary secretion by small increases in [Ca2+ ]i in submandibular gland acinar cells. ABSTRACT We monitored changes in [Ca2+ ]i during salivary secretion in the rat submandibular gland in live animals using a combination of intravital Ca2+ imaging with the ultrasensitive Ca2+ indicator YC-Nano50 and a fibre-optic pressure sensor. Intravenous infusion of ACh (10-720 nmol min-1 ) increased [Ca2+ ]i and salivary flow rate in a dose-dependent manner. Repetitive stimulation with ACh induced equivalent Ca2+ responses and salivary secretion in the same individual animals. The accurate ACh stimulation experiments revealed a clear time lag between the onset of the increase in [Ca2+ ]i and salivary secretion. The time lag with the lowest dose of ACh (30 nmol min-1 ) was 106 s, which shortened to 19 s with the dose used for maximal salivary secretion (360 nmol min-1 ). This time lag might reflect the time required for [Ca2+ ]i to reach the level required to activate molecules for fluid secretion. The resting [Ca2+ ]i in submandibular gland was 37 nm, and [Ca2+ ]i at the onset of salivary secretion was 45-57 nm, irrespective of ACh dose. These results indicate that low [Ca2+ ]i is sufficient to trigger fluid secretion in the rat submandibular gland in vivo.
Collapse
Affiliation(s)
- Akihiro Nezu
- Department of Pharmacology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan
| | - Takao Morita
- Department of Biochemistry, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan
| | - Takeharu Nagai
- Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
| | - Akihiko Tanimura
- Department of Pharmacology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan
| |
Collapse
|
6
|
Ohshima H. Oral biosciences: The annual review 2017. J Oral Biosci 2018. [DOI: 10.1016/j.job.2017.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
7
|
|
8
|
Sato T, Ishii H. Differences in control of parasympathetic vasodilation between submandibular and sublingual glands in the rat. Am J Physiol Regul Integr Comp Physiol 2015; 309:R1432-8. [DOI: 10.1152/ajpregu.00306.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/08/2015] [Indexed: 11/22/2022]
Abstract
We examined blood flow in the submandibular gland (SMGBF) and sublingual gland (SLGBF) during electrical stimulation of the central cut end of the lingual nerve (LN) in the urethane-anesthetized rats using a laser speckle imaging flow meter. LN stimulation elicited intensity- and frequency-dependent SMGBF and SLGBF increases, and the magnitude of the SMGBF increase was higher than that of the SLGBF increase. The increase in both glands was significantly inhibited by intravenous administration of the autonomic cholinergic ganglion blocker hexamethonium. The antimuscarinic agent atropine markedly inhibited the SMGBF increase and partly inhibited the SLGBF increase. The atropine-resistant SLGBF increase was significantly inhibited by infusion of vasoactive intestinal peptide (VIP) receptor antagonist, although administration of VIP receptor antagonist alone had no effect. The recovery time to the basal blood flow level was shorter after LN stimulation than after administration of VIP. However, the recovery time after LN stimulation was significantly delayed by administration of atropine in a dose-dependent manner to the same level as after administration of VIP. Our results indicate that 1) LN stimulation elicits both a parasympathetic SMGBF increase mainly evoked by cholinergic fibers and a parasympathetic SLGBF increase evoked by cholinergic and noncholinergic fibers, and 2) VIP-ergic mechanisms are involved in the noncholinergic SLGBF increase and are activated when muscarinic mechanisms are deactivated.
Collapse
Affiliation(s)
- Toshiya Sato
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Hisayoshi Ishii
- Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| |
Collapse
|
9
|
Nezu A, Morita T, Tojyo Y, Nagai T, Tanimura A. Partial agonistic effects of pilocarpine on Ca2+responses and salivary secretion in the submandibular glands of live animals. Exp Physiol 2015; 100:640-51. [DOI: 10.1113/ep085110] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/14/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Akihiro Nezu
- Department of Pharmacology, School of Dentistry; Health Sciences University of Hokkaido; Ishikari-Tobetsu Hokkaido 061-0293 Japan
| | - Takao Morita
- Department of Pharmacology, School of Dentistry; Health Sciences University of Hokkaido; Ishikari-Tobetsu Hokkaido 061-0293 Japan
| | - Yosuke Tojyo
- Department of Pharmacology, School of Dentistry; Health Sciences University of Hokkaido; Ishikari-Tobetsu Hokkaido 061-0293 Japan
| | - Takeharu Nagai
- The Institute of Scientific and Industrial Research; Osaka University; 8-1 Mihogaoka Ibaraki Osaka 567-0047 Japan
| | - Akihiko Tanimura
- Department of Pharmacology, School of Dentistry; Health Sciences University of Hokkaido; Ishikari-Tobetsu Hokkaido 061-0293 Japan
| |
Collapse
|
10
|
Nezu A, Morita T, Tanimura A. In vitro and in vivo imaging of intracellular Ca2+ responses in salivary gland cells. J Oral Biosci 2015. [DOI: 10.1016/j.job.2015.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
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
|
Kawakami S, Izumi H, Masaki E, Kuchiiwa S, Mizuta K. Role of medullary GABA signal transduction on parasympathetic reflex vasodilatation in the lower lip. Brain Res 2012; 1437:26-37. [DOI: 10.1016/j.brainres.2011.12.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 12/02/2011] [Accepted: 12/13/2011] [Indexed: 12/20/2022]
|
14
|
Ishii H, Niioka T, Watanabe H, Izumi H. Inhibitory effects of excess sympathetic activity on parasympathetic vasodilation in the rat masseter muscle. Am J Physiol Regul Integr Comp Physiol 2007; 293:R729-36. [PMID: 17537835 DOI: 10.1152/ajpregu.00866.2006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The present study was designed to examine the effect of sympathetic tonic activity on parasympathetic vasodilation evoked by the trigeminal-mediated reflex in the masseter muscle in urethane-anesthetized rats. Sectioning of the superior cervical sympathetic trunk (CST) ipsilaterally increased the basal level of blood flow in the masseter muscle (MBF). Electrical stimulation of the peripheral cut end of the CST for 2 min using 2-ms pulses ipsilaterally decreased in a dependent manner the intensity (0.5-10 V) and frequency (0.1-5 Hz) of the MBF. The CST stimulation for 2 min at <0.5 Hz with 5 V using 2-ms pulses seems to be comparable with the spontaneous activity in the CST fibers innervating the masseter vasculature, because this stimulation restored the basal level of the MBF to the presectioned values. Parasympathetic vasodilation evoked by electrical stimulation of the central cut end of the lingual nerve in the masseter muscle was markedly reduced by CST stimulation for 2 min with 5 V using 2-ms pulses in a frequency-dependent manner (0.5-5 Hz). Intravenous administration of phentolamine significantly reduced the vasoconstriction induced by CST stimulation in a dose-dependent manner (0.1-1 mg/kg), but pretreatment with either phentolamine or propranolol failed to affect the sympathetic inhibition of the parasympathetic vasodilation. Our results suggest that 1) excess sympathetic activity inhibits parasympathetic vasodilation in the masseter muscle, and 2) alpha- and beta-adrenoceptors do not contribute to sympathetic inhibition of parasympathetic vasodilation, and thus some other types of receptors must be involved in this response.
Collapse
Affiliation(s)
- Hisayoshi Ishii
- Department of Oral Physiology, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293, Japan
| | | | | | | |
Collapse
|
15
|
Proctor GB, Carpenter GH. Regulation of salivary gland function by autonomic nerves. Auton Neurosci 2006; 133:3-18. [PMID: 17157080 DOI: 10.1016/j.autneu.2006.10.006] [Citation(s) in RCA: 458] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Revised: 10/06/2006] [Accepted: 10/20/2006] [Indexed: 11/24/2022]
Abstract
Oral homeostasis is dependent upon saliva and its content of proteins. Reflex salivary flow occurs at a low 'resting' rate and for short periods of the day more intense taste or chewing stimuli evoke up to ten fold increases in salivation. The secretion of salivary fluid and proteins is controlled by autonomic nerves. All salivary glands are supplied by cholinergic parasympathetic nerves which release acetylcholine that binds to M3 and (to a lesser extent) M1 muscarinic receptors, evoking the secretion of saliva by acinar cells in the endpieces of the salivary gland ductal tree. Most salivary glands also receive a variable innervation from sympathetic nerves which released noradrenaline from which tends to evoke greater release of stored proteins, mostly from acinar cells but also ductal cells. There is some 'cross-talk' between the calcium and cyclic AMP intracellular pathways coupling autonomic stimulation to secretion and salivary protein secretion is augmented during combined stimulation. Other non-adrenergic, non-cholinergic neuropeptides released from autonomic nerves evoke salivary gland secretion and parasympathetically derived vasointestinal peptide, acting through endothelial cell derived nitric oxide, plays a role in the reflex vasodilatation that accompanies secretion. Neuronal type, calcium-activated, soluble nitric oxide within salivary cells appears to play a role in mediating salivary protein secretion in response to autonomimetics. Fluid secretion by salivary glands involves aquaporin 5 and the extent to which the expression of aquaporin 5 on apical acinar cell membranes is upregulated by cholinomimetics remains uncertain. Extended periods of autonomic denervation, liquid diet feeding (reduced reflex stimulation) or duct ligation cause salivary gland atrophy. The latter two are reversible, demonstrating that glands can regenerate provided that the autonomic innervation remains intact. The mechanisms by which nerves integrate with salivary cells during regeneration or during salivary gland development remain to be elucidated.
Collapse
Affiliation(s)
- Gordon B Proctor
- Salivary Research Unit, King's College London Dental Institute, Floor 17 Guy's Tower, London SE1 9RT, UK.
| | | |
Collapse
|
16
|
Mizuta K, Mizuta F, Takahashi M, Ishii H, Niioka T, Izumi H. Effects of isoflurane on parasympathetic vasodilatation in the rat submandibular gland. J Dent Res 2006; 85:379-83. [PMID: 16567563 DOI: 10.1177/154405910608500419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Volatile anesthetics have been known to suppress parasympathetic reflex vasodilatation in the lower lip and palate. However, in the submandibular gland, little is known about the effects of these anesthetics on the parasympathetic vasodilatation elicited by reflex and direct (i.e., non-reflex) activation of the parasympathetic vasodilator mechanisms. Although both parasympathetic vasodilatations were inhibited by isoflurane in a concentration- and time-dependent manner, the effects of continuous administration of the alpha(1)-adrenoceptor agonist methoxamine were markedly different: The reflex vasodilatation was not affected by methoxamine, while the direct vasodilatation was significantly reduced. Picrotoxin (GABA(A) receptor antagonist) attenuated the inhibitory effect of isoflurane on direct vasodilatation and the systemic arterial blood pressure. These findings suggest that the isoflurane-induced inhibitory effects on direct vasodilatation are produced by a decrease of peripheral vascular tone by GABAergic mechanisms, whereas those on the reflex vasodilatation are produced exclusively by the inhibition of the reflex center.
Collapse
Affiliation(s)
- K Mizuta
- Division of Dento-Oral Anesthesiology, Tohoku University Graduate School of Dentistry, Aoba, Sendai, 980-8575, Japan
| | | | | | | | | | | |
Collapse
|
17
|
Ishii H, Niioka T, Sudo E, Izumi H. Evidence for parasympathetic vasodilator fibres in the rat masseter muscle. J Physiol 2005; 569:617-29. [PMID: 16051631 PMCID: PMC1464222 DOI: 10.1113/jphysiol.2005.087643] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The present study was designed to examine (1) whether there are vasodilator fibres in the masseter muscle, and (2) if there are, to establish the neural pathways mediating these responses in urethane-anaesthetized rats. Electrical stimulation of the central cut end of the lingual nerve (LN) elicited intensity- and frequency-dependent increases of the blood flow in the masseter muscle (MBF) and lower lip (LBF). Increases in both the MBF and LBF evoked by the LN stimulation were reduced by hexamethonium in a dose-dependent manner (1-10 mg kg(-1)). Pretreatment with phentolamine or propranolol at a dose of 100 microg kg(-1) had no effect on the increases in either MBF or LBF evoked by LN stimulation. Pretreatment with atropine (100 microg kg(-1)) significantly reduced the MBF increase induced by LN stimulation, but not that in the LBF. The sectioning of the superior cervical sympathetic trunk did not affect the responses. MBF increases occurred with electrical stimulation of the trigeminal ganglion, and these increases were significantly reduced by the administration of hexamethonium and atropine. Lidocaine microinjection into the trigeminal spinal nucleus or salivatory nuclei caused a significant attenuation of the LN-induced MBF increases. When wheat germ agglutinin-horseradish peroxidase (WGA-HRP) was injected into the masseter muscle, labelled neurones were abundantly observed in the otic ganglion. The present study indicates that there are parasympathetic cholinergic and noncholinergic vasodilator fibres originating from cell bodies in the otic ganglion in the rat masseter muscle. The MBF increase evoked by activation of the parasympathetic fibres occurred via the trigeminal mediated reflex, suggesting that the novel parasympathetic vasodilator response may play an important role in the regulation of the haemodynamics of jaw muscles.
Collapse
Affiliation(s)
- Hisayoshi Ishii
- Department of Oral Physiology, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293, Japan
| | | | | | | |
Collapse
|
18
|
Bulbar Pathway for Parasympathetic Reflex Vasodilatation in Orofacial Area. J Oral Biosci 2005. [DOI: 10.1016/s1349-0079(05)80028-3] [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]
|
19
|
Oskutyte D, Ishizuka K, Satoh Y, Murakami T. Ionotropic NMDA receptor evokes an excitatory response in superior salivatory nucleus neurons in anaesthetized rats. Auton Neurosci 2004; 110:98-107. [PMID: 15046733 DOI: 10.1016/j.autneu.2003.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2003] [Revised: 12/10/2003] [Accepted: 12/10/2003] [Indexed: 10/26/2022]
Abstract
Extracellular recordings were taken from preganglionic superior salivatory nucleus (SSN) neurons projecting to submandibular and intra-lingual ganglia, in order to study the action of SSN neurons resulting from ionophoretic application of ionotropic NMDA receptor agonist in urethane-chloralose anaesthetized rats. Single SSN neurons were identified by their antidromic spike responses following stimulation of the chorda-lingual nerve (CLN), chorda tympani branches (CTBs) and the lingual nerve (LN). About one-third (33%, 10/30) of the identified SSN neurons were induced to fire by ionophoretic application of the NMDA receptor agonists used, dl-homocysteic acid (DLH) and N-methyl-D-aspartic acid (NMDA). More than half exhibited firing at high frequencies, often exceeding 40 Hz. About one-fifth (20%; 6/30) of the identified SSN neurons exhibited orthodromic spike responses to the combination of NMDA receptor agonist application and sensory nerve (CLN or LN) stimulus. These excitatory responses evoked by application of NMDA receptor agonist were attenuated (n = 4) by ionophoretic application of DL-2-amino-5-phosphonovaleric acid (AP5; NMDA receptor antagonist). About half (47%) of the neurons did not respond to any combination of NMDA receptor agonist and sensory nerve stimuli. No differences were observed between SSN neurons with B fibre axons and those with C fibre axons in response to ionophoresis of the NMDA receptor agonists. The NMDA-sensitive neurons, which exhibited high frequency firing, were predominantly found in the rostral part of the SSN. In summary, activation of ionotropic NMDA receptors exerts an excitatory effect on about half of the SSN neurons. These data support the view that NMDA receptors are involved in information processing and transmission on SSN neurons.
Collapse
Affiliation(s)
- Diana Oskutyte
- Department of Physiology, The Nippon Dental University, School of Dentistry at Niigata, 1-8 Hamaura-cho Niigata 951-8580, Japan
| | | | | | | |
Collapse
|
20
|
Yasuda M, Izumi H. Trigeminal nerve-mediated reflex arterial blood pressure decrease and vasodilatation in lower lip of the rabbit. Brain Res 2003; 987:59-66. [PMID: 14499946 DOI: 10.1016/s0006-8993(03)03254-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We measured the effects of electrical stimulation of the central cut end of the lingual nerve on lower lip blood flow (LBF) and on arterial blood pressure in urethane-anesthetized, artificially ventilated, cervically vagosympathectomized rabbits. Different effects were observed depending on the stimulus frequency. Increasing the stimulus frequency above 5 Hz produced progressively larger ipsilateral LBF increases until the optimal frequency was reached at 20 Hz. In contrast, stimulation at above 0.5 Hz evoked progressively larger decreases in both contralateral LBF and arterial blood pressure until the optimal frequency was reached at around 10 and 2 Hz, respectively. Thus, the optimal stimulus frequencies for the ipsilateral LBF increase and the arterial blood pressure decrease were widely different. The lingual nerve-evoked change (i.e., fall) in arterial blood pressure showed a significant correlation with the contralateral LBF decrease, but not with the ipsilateral LBF increase. Prior administration of hexamethonium at 10 mg/kg markedly reduced both the ipsilateral LBF increase and arterial blood pressure decrease, although it was more effective against the former than against the latter. Pretreatment with scopolamine (muscarinic-receptor antagonist, 0.1 mg/kg), phentolamine (alpha-adrenoceptor antagonist, 0.1 mg/kg), or propranolol (beta-adrenoceptor antagonist, 0.1 mg/kg) failed to affect either response. However, 1.0 mg/kg phentolamine significantly reduced both responses (P<0.05). These results indicate that, in the rabbit, the LN-evoked reflex increase in ipsilateral LBF is (a) largely independent of any concomitant arterial blood pressure change and (b) probably due to active vasodilatation mediated via parasympathetic mechanisms. In contrast, the evoked decrease in contralateral LBF was proportional to the decrease in arterial blood pressure, suggesting that the former was secondary to the latter.
Collapse
Affiliation(s)
- Makoto Yasuda
- Dento-oral Anesthesiology, Tohoku University Graduate School of Dentistry, 980-8575 Sendai, Japan
| | | |
Collapse
|
21
|
Mizuta K, Kuchiiwa S, Saito T, Mayanagi H, Karita K, Izumi H. Involvement of trigeminal spinal nucleus in parasympathetic reflex vasodilatation in cat lower lip. Am J Physiol Regul Integr Comp Physiol 2002; 282:R492-500. [PMID: 11792659 DOI: 10.1152/ajpregu.2002.282.2.r492] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined whether the trigeminal spinal nucleus (Vsp) forms part of the central mechanism by which electrical stimulation of the central cut end of the lingual nerve (LN) evokes parasympathetic reflex vasodilatation in the lower lip in artificially ventilated, cervically vagosympathectomized cats deeply anesthetized with alpha-chloralose and urethane. For this purpose, we made microinjections within the brain stem to produce nonselective, reversible local anesthesia (lidocaine) or soma-selective, irreversible neurotoxic damage (kainic acid). Local anesthesia of Vsp by microinjection of lidocaine (2%; 1 microl/site) reversibly and significantly reduced the ipsilateral-LN-evoked parasympathetic reflex vasodilatation. Unilateral microinjection of kainic acid (10 mM/site; 1 microl) into Vsp ipsilateral to the stimulated LN led to an irreversible reduction in the reflex vasodilatation but had no effect on the vasodilatation elicited by stimulation of the contralateral LN. Such microinjection of kainic acid into Vsp had no effect on the vasodilatation evoked by electrical stimulation of the ipsilateral inferior salivatory nucleus. Electrical stimulation of Vsp elicited a blood flow increase in the lower lip in an intensity- and frequency-dependent manner, regardless of whether systemic arterial blood pressure rose or fell. Hexamethonium (1.0 mg/kg iv) significantly reduced the vasodilator responses elicited by electrical stimulation of the central cut end of LN or of Vsp, each to a similar degree. After hexamethonium, both vasodilator responses showed time-dependent recovery. These results strongly suggest that Vsp is an important bulbar relay for LN-evoked parasympathetic reflex vasodilatation in the cat lower lip.
Collapse
Affiliation(s)
- Kentaro Mizuta
- Department of Oral Molecular Bioregulation, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | | | | | | | | | | |
Collapse
|
22
|
Sato A, Izumi H, Nakamura I, Karita K. Differences in parasympathetic vasodilator and salivary responses in the cat submandibular gland between lingual and chorda-lingual nerve stimulation. J Dent Res 2001; 80:484-9. [PMID: 11332537 DOI: 10.1177/00220345010800021601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Experimental activation of parasympathetic vasodilatation and salivation in the submandibular gland by a "pseudoreflex" method has definite advantages over other commonly used methods. However, it is unclear which stimulation sites allow for avoidance of direct activation of the parasympathetic efferents to this gland. We examined this question in heavily anesthetized (alpha-chloralose and urethane), artificially ventilated, cervically vago-sympathectomized cats, using the intersection of the chorda-lingual nerve and the submandibular gland duct ("the intersection") as our reference point. Both vasodilatation and salivation evoked by electrical stimulation of the lingual nerve were abolished by section of the chorda-lingual nerve (10 mm proximal to the intersection), provided the stimulation site was distal to the intersection by 4 mm or more. This salivation was abolished by the muscarinic receptor antagonist, scopolamine. Thus, by careful choice of stimulation site, submandibular gland responses mediated solely by reflex parasympathetic mechanisms can be evoked by lingual nerve stimulation in this preparation.
Collapse
Affiliation(s)
- A Sato
- Department of Orofacial Functions, Tohoku University School of Dentistry, Sendai, Japan
| | | | | | | |
Collapse
|