Faculty Collaboration Database

Recurrent laryngeal nerve activation by alpha 2 adrenergic agonists in goats. Respir Physiol 1995 Aug;101(2):129-37

Date

08/01/1995

Pubmed ID

8570915

DOI

10.1016/0034-5687(95)00030-h

Scopus ID

2-s2.0-0029143789 (requires institutional sign-in at Scopus site)   16 Citations

Abstract

The purpose of this study was to test the hypothesis that respiratory and apneas induced by alpha 2 agonists in anesthetized goats are associated with an increase of upper airway expiratory-related activity, rather than a general depression of breathing. Activities of phrenic (Phr) and recurrent laryngeal nerves (RLN) were recorded in response to the alpha 2 agonists clonidine (0.5-3.0 microgram.kg-1 i.v.) or guanabenz (7.0-20.0 micrograms.kg-1 i.v.) in ten chloralose-anesthetized goats. Injection of either alpha 2 agonist resulted in respiratory arrhythmias with a greater than seven-fold increase in TE and a 30% reduction in TI. During apneas RLN expiratory-related activity remained tonic until the next Phr burst, consistent with our hypothesis. Cessation of Phr activity during hypocapnia also resulted in a tonic increase of RLN expiratory activity; and injection of NaCN (50 micrograms.kg-1 i.v.) increased Phr and RLN inspiratory activities, while attenuating RLN expiratory-related activity. Inspiratory and expiratory-related activity of RLN motoneurons appear to be reciprocally modulated by alpha 2 agonists or changes in central or peripheral chemoreceptor drive. The results indicate that central apneas and respiratory arrhythmias may be associated with alpha 2-adrenoceptor modulation of laryngeal expiratory-related activity.

Author List

Hedrick MS, Ryan ML, Bisgard GE

Author

Melinda R. Dwinell PhD Professor in the Physiology department at Medical College of Wisconsin

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

Adrenergic alpha-Agonists
Adrenergic alpha-Antagonists
Animals
Apnea
Benzazepines
Carbon Dioxide
Chemoreceptor Cells
Clonidine
Goats
Guanabenz
Partial Pressure
Phrenic Nerve
Recurrent Laryngeal Nerve
Respiration
Sodium Cyanide