Document Detail


Focal acidosis in the pre-Botzinger complex area of awake goats induces a mild tachypnea.
MedLine Citation:
PMID:  19008492     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
There are widespread chemosensitive areas in the brain with varying effects on breathing. In the awake goat, microdialyzing (MD) 50% CO(2) at multiple sites within the medullary raphe increases pulmonary ventilation (Vi), blood pressure, heart rate, and metabolic rate (Vo(2)) (11), while MD in the rostral and caudal cerebellar fastigial nucleus has a stimulating and depressant effect, respectively, on these variables (17). In the anesthetized cat, the pre-Bötzinger complex (preBötzC), a hypothesized respiratory rhythm generator, increases phrenic nerve activity after an acetazolamide-induced acidosis (31, 32). To gain insight into the effects of focal acidosis (FA) within the preBötzC during physiological conditions, we tested the hypothesis that FA in the preBötzC during wakefulness would stimulate breathing, by increasing respiratory frequency (f). Microtubules were bilaterally implanted into the preBötzC of 10 goats. Unilateral MD of mock cerebral spinal fluid equilibrated with 6.4% CO(2) did not affect Vi, tidal volume (Vt), or f. Unilateral MD of 25 and 50% CO(2) significantly increased Vi and f by 10% (P < 0.05, n = 10, 17 trials), but Vt was unaffected. Bilateral MD of 6.4, 25, or 50% CO(2) did not significantly affect Vi, Vt, or f (P > 0.05, n = 6, 6 trials). MD of 80% CO(2) caused a 180% increase in f and severe disruptions in airflow (n = 2). MD of any level of CO(2) did not result in any significant changes in mean arterial blood pressure, heart rate, or Vo(2). Thus the data suggest that the preBötzC area is chemosensitive, but the responses to FA at this site are unique compared with other chemosensitive sites.
Authors:
K L Krause; H V Forster; S E Davis; T Kiner; J M Bonis; L G Pan; B Qian
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2008-11-13
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  106     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2009 Jan 
Date Detail:
Created Date:  2009-01-09     Completed Date:  2009-02-19     Revised Date:  2010-09-23    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  241-50     Citation Subset:  IM    
Affiliation:
Department of Physiology, Medical College of Wisconsin, Milwaukee,WI, USA. klkrause@mcw.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acidosis / chemically induced,  metabolism,  physiopathology*
Animals
Carbon Dioxide
Chemoreceptor Cells / metabolism*
Disease Models, Animal
Goats
Hydrogen-Ion Concentration
Hypercapnia / chemically induced,  metabolism,  physiopathology*
Microdialysis
Pulmonary Ventilation*
Respiratory Center / metabolism,  physiopathology*
Respiratory Mechanics*
Tidal Volume
Time Factors
Wakefulness*
Grant Support
ID/Acronym/Agency:
HL-25739/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
124-38-9/Carbon Dioxide
Comments/Corrections

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


Previous Document:  Internet-delivered lifestyle physical activity intervention: limited inflammation and antioxidant ca...
Next Document:  Vasoconstrictor responses in the upper and lower limbs to increases in transmural pressure.