Biomaterial Database

Sympathetic rhythms during hyperventilation-induced apnea. 1985

C A Connelly, and R D Wurster

The effect of hyperventilation-induced apnea on the respiratory rhythmicity of sympathetic nerve activity was determined using spectral analysis of sympathetic nerve frequencies. Left phrenic, external intercostal, and inferior cardiac sympathetic nerves were recorded in alpha-chloralose-anesthetized, vagotomized, paralyzed, artificially ventilated cats. The respiratory modulation of sympathetic activity during normoventilation was indicated by spectral peaks of sympathetic activity coinciding with respiratory frequencies determined from the phrenic nerve activity of each cat. The spectral peaks of respiratory-related sympathetic activity disappeared during hyperventilation-induced apnea and then reappeared with the return of phrenic nerve activity when normoventilation was resumed. Although sympathetic activity lost its respiratory modulation during hyperventilation, baroreceptor-mediated bilateral carotid occlusion responses and electrocardiogram (R wave)-triggered computer summation of cardiac related sympathetic activity were unaffected. Hence central respiratory inputs on sympathetic pathways in the central nervous system best explain the origin of respiratory-related sympathetic rhythms. Independent sympathetic rhythms of apparent nonrespiratory origin may be due to artificial ventilator influences, baroreflex-autonomic oscillation loops, or Mayer waves.

UI	MeSH Term	Description	Entries
D006985	Hyperventilation	A pulmonary ventilation rate faster than is metabolically necessary for the exchange of gases. It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide.	Hyperventilations
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
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
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
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D002628	Chemoreceptor Cells	Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.	Chemoreceptive Cells,Cell, Chemoreceptive,Cell, Chemoreceptor,Cells, Chemoreceptive,Cells, Chemoreceptor,Chemoreceptive Cell,Chemoreceptor Cell
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
D001049	Apnea	A transient absence of spontaneous respiration.	Apneas
D013057	Spectrum Analysis	The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Spectroscopy,Analysis, Spectrum,Spectrometry