Biomaterial Database

Modulation of respiratory responses to carotid sinus nerve stimulation by brain hypoxia. 1992

J E Melton, and Q P Yu, and J A Neubauer, and N H Edelman

Department of Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick 08903-0019.

This study examines the effect of progressive isocapnic CO hypoxemia on respiratory afterdischarge and the phrenic neurogram response to supramaximal carotid sinus nerve (CSN) stimulation. Twelve anesthetized, vagotomized, peripherally chemodenervated, ventilated cats with blood pressure controlled were studied. During isocapnic hypoxemia, the amplitude of the phrenic neurogram was progressively depressed. In contrast, the increase in peak phrenic amplitude produced by CSN stimulation was unchanged, suggesting that the central respiratory response to CSN stimulation is unaffected by progressive hypoxemia. The time constant of respiratory afterdischarge (tau) was calculated from best-fit plots of phrenic amplitude vs. time after cessation of CSN stimulation. Under control conditions the value of tau was 57.7 +/- 3 (SE) s (n = 12). During progressive isocapnic hypoxemia, tau decreased as a linear function of arterial O2 content (CaO2) such that a 40% reduction of CaO2 resulted in a 48% reduction in tau. This reduction of respiratory afterdischarge may contribute to the genesis of periodic breathing during hypoxia.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D010791	Phrenic Nerve	The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.	Nerve, Phrenic,Nerves, Phrenic,Phrenic Nerves
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
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D002248	Carbon Monoxide	Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)	Monoxide, Carbon
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
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
D002534	Hypoxia, Brain	A reduction in brain oxygen supply due to ANOXEMIA (a reduced amount of oxygen being carried in the blood by HEMOGLOBIN), or to a restriction of the blood supply to the brain, or both. Severe hypoxia is referred to as anoxia and is a relatively common cause of injury to the central nervous system. Prolonged brain anoxia may lead to BRAIN DEATH or a PERSISTENT VEGETATIVE STATE. Histologically, this condition is characterized by neuronal loss which is most prominent in the HIPPOCAMPUS; GLOBUS PALLIDUS; CEREBELLUM; and inferior olives.	Anoxia, Brain,Anoxic Encephalopathy,Brain Hypoxia,Cerebral Anoxia,Encephalopathy, Hypoxic,Hypoxic Encephalopathy,Anoxia, Cerebral,Anoxic Brain Damage,Brain Anoxia,Cerebral Hypoxia,Hypoxia, Cerebral,Hypoxic Brain Damage,Anoxic Encephalopathies,Brain Damage, Anoxic,Brain Damage, Hypoxic,Damage, Anoxic Brain,Damage, Hypoxic Brain,Encephalopathies, Anoxic,Encephalopathies, Hypoxic,Encephalopathy, Anoxic,Hypoxic Encephalopathies
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical