Abstract
Functional changes in afferent, central, and efferent components of the arterial baroreflex circuitry in F344 rats following chronic intermittent hypoxia (CIH)
The FASEB journal, Vol.21(6), pp.A823-A823
2007
DOI: 10.1096/fasebj.21.6.A823-a
Abstract
Baroreflex control of heart rate (HR) is reduced following CIH. However, the location and nature of such a functional deficit remain unclear. We hypothesized that CIH leads to dysfunction of Baroreceptor afferent, vagal efferent, and central components of the baroreflex circuitry. F344 rats (4 months) were exposed to room air (RA, n=8) or CIH (n=9) for 35 days, and were then anesthetized with isoflurane. Baroreceptor afferent function was characterized by measuring % changes of integrated aortic depressor nerve activity (ADNA) in response to nitroprusside‐and phenylephrine‐induced changes in mean arterial blood pressure (MAP). Data were fitted to a sigmoidal logistic function curve. The central mediation of the bradycardic responses to the left ADN stimulation and the HR response to the right vagus stimulation were assessed under Ketamine‐Acepromazine anesthesia. CIH increased Gmax (RA, 3.8+/−0.5%/mmHg; CIH, 5.1+/−0.3%/mmHg; p<0.05), maximal ADNA (RA, 261+/−30%; CIH, 359+/−15%; p<0.01), and ADNA range (RA, 259+/−37%; CIH, 354+/−15%; p<0.05), whereas other parameters were unaffected. CIH also reduced HR responses to ADN stimulation and increased the responses to vagal efferent stimulation at low frequencies (ANOVA, p<0.05). Therefore, CIH decreases central baroreflex control of HR, but augments vagal afferent function and efferent control. These data suggest that changes in peripheral autonomic components may compensate for the functional deficits that develop in the central autonomic control of HR following CIH. NIH AG‐021020, HL‐79636, HL‐69932
Details
- Title: Subtitle
- Functional changes in afferent, central, and efferent components of the arterial baroreflex circuitry in F344 rats following chronic intermittent hypoxia (CIH)
- Creators
- He Gu - Univ. of Central FloridaMin Lin - Univ. of Central FloridaDavid Gozal - University of LouisvilleKarie E. Scrogin - Loyola Univ. ChicagoMark W Chapleau - University of IowaZixi Cheng - Univ. of Central Florida
- Resource Type
- Abstract
- Publication Details
- The FASEB journal, Vol.21(6), pp.A823-A823
- Publisher
- The Federation of American Societies for Experimental Biology
- DOI
- 10.1096/fasebj.21.6.A823-a
- ISSN
- 0892-6638
- eISSN
- 1530-6860
- Number of pages
- 1
- Language
- English
- Date published
- 2007
- Academic Unit
- Molecular Physiology and Biophysics; Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Internal Medicine
- Record Identifier
- 9984302197902771
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