Naloxone enhances respiratory output in cats

Edward Lawson, T. G. Waldrop, F. L. Eldridge

Research output: Contribution to journalArticle

Abstract

To investigate the physiological role of opiate receptors and opiatelike neurotransmitters, which are present in brain-stem respiratory centers, we administered naloxone to 10 cats by intravenous injection. These animals were vagotomized, paralyzed, and servo-ventilated to maintain constant end-tidal CO2; in addition, their carotid sinus nerves were sectioned bilaterally. Respiratory output was assessed by integration of phrenic nerve activity. Control saline infusions had no effect on respiratory output. However, administration of naloxone (0.4 mg/kg) caused phrenic minute output to increase significantly in each of five anesthetized cerebrate cats (control 7,272 ± 1.615 U/min; 30 min postnaloxone 12,920 ± 3,857 U/min; P <0.05) and five unanesthetized decerebrate cats (control 10,368 ± 1,222 U/min; naloxone 14,648 ± 3,225 U/min; P <0.05). In addition to the effect on phrenic minute output, naloxone infusion resulted in an increase of the inspiratory rate of rise of phrenic nerve activity in each cat. There was no change in the ratio of inspiratory duration to total respiratory period (TI/Ttot). Because naloxone is a specific opiate antagonist, we suggest that endogenous opiatelike neurotransmitters (endorphins) may modulate central inspiratory drive.

Original languageEnglish (US)
Pages (from-to)1105-1111
Number of pages7
JournalJournal of Applied Physiology Respiratory Environmental and Exercise Physiology
Volume47
Issue number5
StatePublished - 1979
Externally publishedYes

Fingerprint

Naloxone
Cats
Phrenic Nerve
Diaphragm
Neurotransmitter Agents
Opiate Alkaloids
Respiratory Center
Endorphins
Carotid Sinus
Opioid Receptors
Intravenous Injections
Brain Stem

ASJC Scopus subject areas

  • Endocrinology
  • Physiology

Cite this

Naloxone enhances respiratory output in cats. / Lawson, Edward; Waldrop, T. G.; Eldridge, F. L.

In: Journal of Applied Physiology Respiratory Environmental and Exercise Physiology, Vol. 47, No. 5, 1979, p. 1105-1111.

Research output: Contribution to journalArticle

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