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Differential respiratory muscle recruitment induced by clonidine in awake goats. J Appl Physiol (1985) 1998 Apr;84(4):1198-207 PMID: 9516185

Pubmed ID



The purpose of this study was to test the hypothesis that dysrhythmic breathing induced by the alpha2-agonist clonidine is accompanied by differential recruitment of respiratory muscles. In adult goats (n = 14) electromyographic (EMG) measurements were made from inspiratory muscles (diaphragm and parasternal intercostal) and expiratory muscles [triangularis sterni (TS) and transversus abdominis (Abd)]. EMG of the thyroarytenoid (TA) muscle was used as an index of upper airway (glottal) patency. Peak EMG activities of all spinal inspiratory and expiratory muscles were augmented by central and peripheral chemoreceptor stimuli. Phasic TA was apparent in the postinspiratory phase of the breathing cycle under normoxic conditions. During dysrhythmic breathing episodes induced by clonidine, TS and Abd activities were attenuated or abolished, whereas diaphragm and parasternal intercostal activities were unchanged. There was no tonic activation of TS or Abd EMG during apneas; however, TA activity became tonic throughout the apnea. We conclude that 1) alpha2-adrenoceptor stimulation results in differential recruitment of respiratory muscles during respiratory dysrhythmias and 2) apneas are accompanied by active glottic closure in the awake goat.

Author List

Hedrick MS, Dwinell MR, Janssen PL, Pizarro J, Bisgard GE


Melinda R. Dwinell PhD Center Associate Director, Associate Professor in the Physiology department at Medical College of Wisconsin


2-s2.0-0031944642   17 Citations

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

Adrenergic alpha-2 Receptor Agonists
Adrenergic alpha-Agonists
Respiratory Mechanics
Respiratory Muscles
jenkins-FCD Prod-321 98992d628744e349846c2f62ac68f241d7e1ea70