Faculty Collaboration Database

Important role of carotid afferents in control of breathing. J Appl Physiol (1985) 1998 Oct;85(4):1299-306

Date

10/07/1998

Pubmed ID

9760320

DOI

10.1152/jappl.1998.85.4.1299

Scopus ID

2-s2.0-0031694690 (requires institutional sign-in at Scopus site)   75 Citations

Abstract

The purpose of the present study was to determine the effect on breathing in the awake state of carotid body denervation (CBD) over 1-2 wk after denervation. Studies were completed on adult goats repeatedly before and 1) for 15 days after bilateral CBD (n = 8), 2) for 7 days after unilateral CBD (n = 5), and 3) for 15 days after sham CBD (n = 3). Absence of ventilatory stimulation when NaCN was injected directly into a common carotid artery confirmed CBD. There was a significant (P < 0.01) hypoventilation during the breathing of room air after unilateral and bilateral CBD. The maximum PaCO2 increase (8 Torr for unilateral and 11 Torr for bilateral) occurred approximately 4 days after CBD. This maximum was transient because by 7 (unilateral) to 15 (bilateral) days after CBD, PaCO2 was only 3-4 Torr above control. CO2 sensitivity was attenuated from control by 60% on day 4 after bilateral CBD and by 35% on day 4 after unilateral CBD. This attenuation was transient, because CO2 sensitivity returned to control temporally similar to the return of PaCO2 during the breathing of room air. During mild and moderate treadmill exercise 1-8 days after bilateral CBD, PaCO2 was unchanged from its elevated level at rest, but, 10-15 days after CBD, PaCO2 decreased slightly from rest during exercise. These data indicate that 1) carotid afferents are an important determinant of rest and exercise breathing and ventilatory CO2 sensitivity, and 2) apparent plasticity within the ventilatory control system eventually provides compensation for chronic loss of these afferents.

Author List

Pan LG, Forster HV, Martino P, Strecker PJ, Beales J, Serra A, Lowry TF, Forster MM, Forster AL

Author

Hubert V. Forster PhD Professor in the Physiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Afferent Pathways
Animals
Carbon Dioxide
Carotid Artery, Common
Carotid Body
Denervation
Female
Functional Laterality
Goats
Hypoxia
Injections, Intra-Arterial
Lung
Male
Orchiectomy
Ovariectomy
Oxygen
Partial Pressure
Respiratory Mechanics
Sodium Cyanide
Time Factors