BIOMAT Database Logo BIOMAT Database Logo

Sustained microgravity reduces the human ventilatory response to hypoxia but not to hypercapnia. 2000

G K Prisk, and A R Elliott, and J B West
Department of Medicine, University of California, San Diego, La Jolla, California 92093-0931, USA. kprisk@ucsd.edu

We measured the isocapnic hypoxic ventilatory response and the hypercapnic ventilatory response by using rebreathing techniques in five normal subjects (ages 37-47 yr) before, during, and after 16 days of exposure to microgravity (microG). Control measurements were performed with the subjects in the standing and supine postures. In both microG and in the supine position, the hypoxic ventilatory response, as measured from the slope of ventilation against arterial O(2) saturation, was greatly reduced, being only 46 +/- 10% (microG) and 52 +/- 11% (supine) of that measured standing (P < 0.01). During the hypercapnic ventilatory response test, the ventilation at a PCO(2) of 60 Torr was not significantly different in microG (101 +/- 5%) and the supine position (89 +/- 3%) from that measured standing. Inspiratory occlusion pressures agreed with these results. The findings can be explained by inhibition of the hypoxic but not hypercapnic drive, possibly as a result of an increase in blood pressure in carotid baroreceptors in microG and the supine position.

UI MeSH Term Description Entries
D008297 Male Males
D008875 Middle Aged An adult aged 45 - 64 years. Middle Age
D010100 Oxygen An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration. Dioxygen,Oxygen-16,Oxygen 16
D010313 Partial Pressure The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed) Partial Pressures,Pressure, Partial,Pressures, Partial
D011187 Posture The position or physical attitude of the body. Postures
D012143 Respiratory Physiological Phenomena Physiological processes and properties of the RESPIRATORY SYSTEM as a whole or of any of its parts. Respiratory Physiologic Processes,Respiratory Physiological Processes,Respiratory Physiology,Physiology, Respiratory,Pulmonary Physiological Phenomena,Pulmonary Physiological Phenomenon,Pulmonary Physiological Process,Pulmonary Physiological Processes,Respiratory Physiological Concepts,Respiratory Physiological Phenomenon,Respiratory Physiological Process,Concept, Respiratory Physiological,Concepts, Respiratory Physiological,Phenomena, Pulmonary Physiological,Phenomena, Respiratory Physiological,Phenomenas, Pulmonary Physiological,Phenomenas, Respiratory Physiological,Phenomenon, Pulmonary Physiological,Phenomenon, Respiratory Physiological,Phenomenons, Pulmonary Physiological,Phenomenons, Respiratory Physiological,Physiologic Processes, Respiratory,Physiological Concept, Respiratory,Physiological Concepts, Respiratory,Physiological Phenomena, Pulmonary,Physiological Phenomena, Respiratory,Physiological Phenomenas, Pulmonary,Physiological Phenomenas, Respiratory,Physiological Phenomenon, Pulmonary,Physiological Phenomenon, Respiratory,Physiological Phenomenons, Pulmonary,Physiological Phenomenons, Respiratory,Physiological Process, Pulmonary,Physiological Process, Respiratory,Physiological Processes, Pulmonary,Physiological Processes, Respiratory,Process, Pulmonary Physiological,Process, Respiratory Physiological,Processes, Pulmonary Physiological,Pulmonary Physiological Phenomenas,Pulmonary Physiological Phenomenons,Respiratory Physiological Concept,Respiratory Physiological Phenomenas,Respiratory Physiological Phenomenons
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
D005260 Female Females
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man

Related Publications

G K Prisk, and A R Elliott, and J B West
Medullary serotonergic neurones modulate the ventilatory response to hypercapnia, but not hypoxia in conscious rats.
July 2005, The Journal of physiology,
G K Prisk, and A R Elliott, and J B West
[Ventilatory response to hypoxia and hypercapnia].
April 1997, Nihon rinsho. Japanese journal of clinical medicine,
G K Prisk, and A R Elliott, and J B West
Serotonin transporter knockout mice have a reduced ventilatory response to hypercapnia (predominantly in males) but not to hypoxia.
May 2008, The Journal of physiology,
G K Prisk, and A R Elliott, and J B West
Ventilatory response to sustained hypoxia during exercise.
June 1991, Medicine and science in sports and exercise,
G K Prisk, and A R Elliott, and J B West
Hyperosmolality alters the ventilatory response to acute hypercapnia and hypoxia.
November 1993, Respiration physiology,
G K Prisk, and A R Elliott, and J B West
Effects of 20% nitrous oxide on the ventilatory response to hypercapnia and sustained isocapnic hypoxia in man.
January 1994, British journal of anaesthesia,
G K Prisk, and A R Elliott, and J B West
Theophylline does not increase ventilatory responses to hypercapnia or hypoxia.
December 1992, The American review of respiratory disease,
G K Prisk, and A R Elliott, and J B West
Ventilatory response to sustained hypoxia in normal adults.
September 1986, Journal of applied physiology (Bethesda, Md. : 1985),
G K Prisk, and A R Elliott, and J B West
Ventilatory response to randomly modulated hypercapnia and hypoxia in humans.
May 1994, Journal of applied physiology (Bethesda, Md. : 1985),
G K Prisk, and A R Elliott, and J B West
Ventilatory response to hypercapnia.
October 1977, Seminars in perinatology,
Copied contents to your clipboard!