Reflex arc of the teeth clenching-induced pressor response in rats

• Published in: The journal of physiological sciences 2018-01, Vol.68 (1), p.89-100
• Main Authors: Shoji, Ichiro, Kemuriyama, Takehito, Tandai-Hiruma, Megumi, Maruyama, Satoshi, Tashiro, Akimasa, Yokoe, Hidetaka, Nishida, Yasuhiro
• Format: Article
• Language: English
• Subjects: Anesthesia; Animals; Atropine; Blood pressure; Blood Pressure - drug effects; Blood Pressure - physiology; Circulatory system; Dantrolene - administration & dosage; Electric Stimulation - methods; Electrical stimuli; Gadolinium; Heart beat; Heart rate; Heart Rate - drug effects; Heart Rate - physiology; Male; Mastication; Mechanoreceptors; Muscles; Neurons, Afferent - drug effects; Neurons, Afferent - physiology; Neurons, Efferent - drug effects; Neurons, Efferent - physiology; Nitrates; Original Paper; Periodontics; Rats; Rats, Sprague-Dawley; Reflex - drug effects; Reflex - physiology; Sensory neurons; Sympathetic nerves; Sympathetic Nervous System - drug effects; Sympathetic Nervous System - physiology; Teeth; Tooth - drug effects; Tooth - physiology; Trigeminal ganglion; Trigeminal Ganglion - drug effects; Trigeminal Ganglion - physiology
• ISSN: 1880-6546; 1880-6562
• DOI: 10.1007/s12576-016-0513-9

Although "teeth clenching" induces pressor response, the reflex tracts of the response are unknown. In this study, dantrolene administration inhibited teeth clenching generated by electrical stimulation of the masseter muscles and completely abolished the pressor response. In addition, trigeminal ganglion block or hexamethonium administration completely abolished the pressor response. Local anesthesia of molar regions significantly reduced the pressor response to 27 ± 10%. Gadolinium (mechanoreceptor blocker of group III muscle afferents) entrapment in masticatory muscles also significantly reduced the pressor response to 62 ± 7%. Although atropine methyl nitrate administration did not change the pressor response, a significant dose-dependent augmentation of heart rate was observed. These results indicate that both periodontal membrane and mechanoreceptors in masticatory muscles are the receptors for the pressor response, and that the afferent and efferent pathways of the pressor response pass through the trigeminal afferent nerves and sympathetic nerves, respectively.