Document Detail


Hypoxic ventilatory response during light and dark periods and the involvement of histamine H1 receptor in mice.
MedLine Citation:
PMID:  17626131     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Ventilation oscillates throughout a day in parallel with oscillations in metabolic rate. Histamine affects ventilation and the balance of the energy metabolism via H1 receptors in the brain. We tested the hypothesis that the ventilatory response to hypoxia varies between light and dark periods and that histamine H1 receptors are required for the circadian variation, using wild-type (WT) and histamine H1 receptor knockout (H1RKO) mice. Mice were exposed to hypoxic gas (7% O(2) + 3% CO(2) in N(2)) during light and dark periods. Ventilation initially increased and then declined. In WT mice, minute ventilation (.Ve) during hypoxia was higher in the dark period than in the light period, which was an upward shift along with the baseline ventilation. Hypoxia decreased the metabolic rate, whereas O2 consumption (.VO(2)) and CO(2) excretion were higher in the dark period than in the light period. However, in H1RKO mice, changes in Ve during hypoxia between light and dark periods were minimal, because .Ve was increased relative to .VO(2), particularly in the light period. In H1RKO mice, the HCO(3)(-) concentration and base excess values were increased in arterial blood, and the level of ketone bodies was increased in the serum, indicating that metabolic acidosis occurred. Respiratory compensation takes part in the .Ve increase relative to .VO(2) during hypoxia. These results suggested that changes in .Ve during hypoxia vary between light and dark periods and that H1 receptors play a role in circadian variation in .Ve through control of the acid-base status and metabolism in mice.
Authors:
Yasuyoshi Ohshima; Michiko Iwase; Masahiko Izumizaki; Takashi Ishiguro; Mitsuko Kanamaru; Hideaki Nakayama; Fumitake Gejyo; Ikuo Homma
Publication Detail:
Type:  Journal Article     Date:  2007-07-11
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  293     ISSN:  0363-6119     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2007 Sep 
Date Detail:
Created Date:  2007-08-31     Completed Date:  2007-10-17     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R1350-6     Citation Subset:  IM    
Affiliation:
2nd Dept. of Physiology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
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MeSH Terms
Descriptor/Qualifier:
Aerobiosis
Animals
Anoxia / physiopathology*
Blood Gas Analysis
Blood Glucose / metabolism
Carbon Dioxide / metabolism
Circadian Rhythm / physiology
Darkness
Light
Lipids / blood
Mice
Mice, Inbred C57BL
Mice, Knockout
Oxygen Consumption / physiology
Plethysmography
Pulmonary Gas Exchange / physiology
Receptors, Histamine H1 / physiology*
Respiratory Mechanics / physiology*
Chemical
Reg. No./Substance:
0/Blood Glucose; 0/Lipids; 0/Receptors, Histamine H1; 124-38-9/Carbon Dioxide

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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