Excitation of baroreceptors depresses A- and C-components of the somato-cardiac sympathetic reflex in anesthetized rats. 1998

W M Li, and X Liu, and M Kumada, and A Sato
Department of Molecular and Cellular Physiology, Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan. satoakio@center.tmig.or.jp

The effect of baroreceptor activation on somato-cardiac sympathetic reflex discharges was examined in urethane-anesthetized, vagotomized, and artificially ventilated rats. Single shock stimulation of myelinated (A) and unmyelinated (C) fibers in the tibial nerve of the left hindlimb elicited two separate excitatory reflex discharge components in a branch of the cardiac sympathetic nerve. They are termed the A- and C-components of the somato-cardiac sympathetic reflex discharges. When aortic nerves (AN) and carotid sinus nerves (CSN) were intact, a sudden increase in mean arterial blood pressure to about 150 mmHg induced by I.V. injection of phenylephrine (50 micro/kg) depressed the A- and C-components by up to 47 +/- 5.4 and 37 +/- 7.7% of the control values, respectively. However, bilateral sino-aortic denervation completely abolished the pressure-induced depression of both components. We conclude that baroreceptor afferent signals from the AN and CSN inhibit both A- and C-components of the excitatory somato-cardiac sympathetic reflex discharges. This and other previous evidence mentioned in the text indicate that inhibitory cardiac sympathetic reflexes originating from arterial baroreceptors and excitatory ones originating from somatic afferents interact, probably at the brainstem.

UI MeSH Term Description Entries
D009412 Nerve Fibers Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM. Cerebellar Mossy Fibers,Mossy Fibers, Cerebellar,Cerebellar Mossy Fiber,Mossy Fiber, Cerebellar,Nerve Fiber
D009413 Nerve Fibers, Myelinated A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves. A Fibers,B Fibers,Fiber, Myelinated Nerve,Fibers, Myelinated Nerve,Myelinated Nerve Fiber,Myelinated Nerve Fibers,Nerve Fiber, Myelinated
D010656 Phenylephrine An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent. (R)-3-Hydroxy-alpha-((methylamino)methyl)benzenemethanol,Metaoxedrin,Metasympatol,Mezaton,Neo-Synephrine,Neosynephrine,Phenylephrine Hydrochloride,Phenylephrine Tannate,Neo Synephrine,Tannate, Phenylephrine
D011311 Pressoreceptors Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls. Baroreceptors,Receptors, Stretch, Arterial,Receptors, Stretch, Vascular,Stretch Receptors, Arterial,Stretch Receptors, Vascular,Arterial Stretch Receptor,Arterial Stretch Receptors,Baroreceptor,Pressoreceptor,Receptor, Arterial Stretch,Receptor, Vascular Stretch,Receptors, Arterial Stretch,Receptors, Vascular Stretch,Stretch Receptor, Arterial,Stretch Receptor, Vascular,Vascular Stretch Receptor,Vascular Stretch Receptors
D001794 Blood Pressure PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS. Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D002346 Carotid Sinus The dilated portion of the common carotid artery at its bifurcation into external and internal carotids. It contains baroreceptors which, when stimulated, cause slowing of the heart, vasodilatation, and a fall in blood pressure. Sinus, Carotid
D003714 Denervation The resection or removal of the nerve to an organ or part. Laser Neurectomy,Neurectomy,Peripheral Neurectomy,Radiofrequency Neurotomy,Denervations,Laser Neurectomies,Neurectomies,Neurectomies, Laser,Neurectomies, Peripheral,Neurectomy, Laser,Neurectomy, Peripheral,Neurotomies, Radiofrequency,Neurotomy, Radiofrequency,Peripheral Neurectomies,Radiofrequency Neurotomies
D005121 Extremities The farthest or outermost projections of the body, such as the HAND and FOOT. Limbs,Extremity,Limb
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001011 Aorta The main trunk of the systemic arteries. Aortas

Related Publications

W M Li, and X Liu, and M Kumada, and A Sato
October 1996, Neuroscience letters,
W M Li, and X Liu, and M Kumada, and A Sato
January 2000, Journal of the autonomic nervous system,
W M Li, and X Liu, and M Kumada, and A Sato
December 1969, Brain research,
W M Li, and X Liu, and M Kumada, and A Sato
July 1996, Neuroscience letters,
W M Li, and X Liu, and M Kumada, and A Sato
January 2002, Acupuncture & electro-therapeutics research,
W M Li, and X Liu, and M Kumada, and A Sato
April 2006, The journal of physiological sciences : JPS,
W M Li, and X Liu, and M Kumada, and A Sato
March 1996, [Hokkaido igaku zasshi] The Hokkaido journal of medical science,
W M Li, and X Liu, and M Kumada, and A Sato
March 1991, Journal of cardiovascular pharmacology,
W M Li, and X Liu, and M Kumada, and A Sato
October 1992, Journal of anesthesia,
W M Li, and X Liu, and M Kumada, and A Sato
January 2007, Journal of applied physiology (Bethesda, Md. : 1985),
Copied contents to your clipboard!