Biomaterial Database

Ventilatory interaction between hypoxia and [H+] at chemoreceptors of man. 1975

R A Gabel, and R B Weiskopf

By measuring ventilation during isocapnic progressive hypoxia, peripheral chemoreceptor sensitivity to acute hypoxia (deltaV40) was measured in five normal young men under four sets of conditions: 1) at sea level at the subject's resting PCO2, 2) at sea level with PCO2 5 Torr above resting PCO2, 3) after 24 h at a simulated altitude of 4,267 m (PB = 447 Torr) at the subject's resting PCO2 measured during acute hyperoxia, and 4) after 24 h at high altitude, with PCO2 elevated to the subject's sea-level resting PCO2. With this experimental design, we were able to systematically vary the PCO2 and [H+] at the peripheral and central chemoreceptors of man. When mean pHa was decreased from 7.424 to 7.377 without significant change in PACO2, the mean deltaV40 increased from 18.0 to 55.9 1/min. Conversely, when mean PACO2 was altered between 33.8 and 41.6 Torr with pHa held relatively constant, the mean deltaV40 did not change. This suggests that it is the H+ and not CO2 which interacts with hypoxia in stimulating the ventilation of man. An additional finding was that the intrinsic sensitivity of the peripheral chemoreceptors to acute hypoxia did not change during 24 h of acclimatization to high altitude.

UI	MeSH Term	Description	Entries
D008176	Lung Volume Measurements	Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.	Lung Capacities,Lung Volumes,Capacity, Lung,Lung Capacity,Lung Volume,Lung Volume Measurement,Measurement, Lung Volume,Volume, Lung
D008297	Male		Males
D008451	Maximal Voluntary Ventilation	Measure of the maximum amount of air that can be breathed in and blown out over a sustained interval such as 15 or 20 seconds. Common abbreviations are MVV and MBC.	Maximal Breathing Capacity,MVV (Ventilation),Breathing Capacities, Maximal,Breathing Capacity, Maximal,Capacities, Maximal Breathing,Capacity, Maximal Breathing,Maximal Breathing Capacities,Maximal Voluntary Ventilations,Ventilation, Maximal Voluntary,Ventilations, Maximal Voluntary,Voluntary Ventilation, Maximal,Voluntary Ventilations, Maximal
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
D002414	Cations, Monovalent	Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.	Monovalent Cation,Cation, Monovalent,Monovalent Cations
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
D004780	Environment, Controlled	A state in which the environs of hospitals, laboratories, domestic and animal housing, work places, spacecraft, and other surroundings are under technological control with regard to air conditioning, heating, lighting, humidity, ventilation, and other ambient features. The concept includes control of atmospheric composition. (From Jane's Aerospace Dictionary, 3d ed)	Clean Rooms,Laminar Air-Flow Areas,Controlled Environment,Area, Laminar Air-Flow,Clean Room,Controlled Environments,Environments, Controlled,Laminar Air Flow Areas,Laminar Air-Flow Area,Room, Clean
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006859	Hydrogen	The first chemical element in the periodic table with atomic symbol H, and atomic number 1. Protium (atomic weight 1) is by far the most common hydrogen isotope. Hydrogen also exists as the stable isotope DEUTERIUM (atomic weight 2) and the radioactive isotope TRITIUM (atomic weight 3). Hydrogen forms into a diatomic molecule at room temperature and appears as a highly flammable colorless and odorless gas.	Protium,Hydrogen-1
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations