| The respiratory response of the new-born lamb to inhaled CO-2 with and without accompanying hypoxia. | |
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MedLine Citation:
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PMID: 5965899 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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1. The respiratory response to inhaled CO(2) was measured in twenty unanaesthetized new-born lambs aged 4 hr-10 days. Measurement of resting arterial pH, P(CO2) and plasma bicarbonate showed a non-respiratory acidosis immediately after birth which was corrected in the first 24-28 hr: thereafter, the acid-base pattern was of a compensated respiratory alkalosis.2. When CO(2) was added to the inspired gases and resting arterial oxygen tension (P(a), (O2)) was controlled, the average increase in minute ventilation (V) was 0.075 l.min(-1).kg(-1).mm Hg, P(a), (CO2) (-1) and duplicate responses in the same lamb differed by 6-22.5%.3. The slope of the V/P(a), (CO2) line (S) varied inversely with P(a), (O2). In one lamb, severe hypoxia (P(a), (O2) = 21 mm Hg) caused a marked depression of the slope.4. Neither the slope S nor the horizontal intercept B of the lines was related to the age of the lamb. B was not related to pH(a) and only slightly affected by acute hypoxia. B was related to arterial [HCO(3) (-)] and values for both were reduced with the acid-base disturbances seen in the first 10 days after birth. Evidence was given which suggested that the response of the new-born lamb to inhaled CO(2) was similar to that of man acclimatized to a P(a), (O2) of 70-75 mm Hg.5. In the lightly anaesthetized lamb, bilateral section of the sinus nerves caused a small reduction in the sensitivity to inhaled 5% CO(2) in air, an increase in the respiratory lag and a reduction in the rate at which V increased.6. It was concluded that, in the new-born lamb, the carotid chemo-receptors are involved in the response to inhaled CO(2) and that hypoxia potentiates this response. |
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Authors:
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M J Purves |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: The Journal of physiology Volume: 185 ISSN: 0022-3751 ISO Abbreviation: J. Physiol. (Lond.) Publication Date: 1966 Jul |
Date Detail:
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Created Date: 1967-07-30 Completed Date: 1967-07-30 Revised Date: 2009-11-18 |
Medline Journal Info:
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Nlm Unique ID: 0266262 Medline TA: J Physiol Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 78-94 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Acidosis
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etiology Animals Animals, Newborn / physiology* Anoxia / physiopathology* Bicarbonates / blood Blood Gas Analysis Carbon Dioxide / pharmacology* Carotid Body / physiology* Hydrogen-Ion Concentration Respiration / physiology* Sheep |
| Chemical | |
Reg. No./Substance:
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0/Bicarbonates; 124-38-9/Carbon Dioxide |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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