Effects of acute and chronic cocaine on the respiratory pattern, and ventilatory responses to hypoxia and hypercapnia, were studied in awake and anesthetized adult rats. In addition, effects of the drug on vagal reflexes, respiratory mechanics and gas exchange were investigated in anesthetized animals. / Acute cocaine elicited rapid and shallow breathing in awake rats. Ventilatory excitation, but not tachypnea, was present in anesthetized animals. In untreated rats, respiratory rate (f) increased during 10% O$ sb2$ and 5% CO$ sb2$ exposures; f decreased after cocaine, but in absolute terms, it was still higher after than before treatment. In anesthetized animals, augmentation of minute ventilation and f recorded in response to low O$ sb2$ and high CO$ sb2$ were higher with than without acute cocaine. / Chronic cocaine depressed ventilatory responses to both stimuli in awake, but not in the anesthetized chronic rats. Neither acute nor chronic cocaine affected respiratory mechanics and diffusion capacity of the lungs. Finally, strength of the expiratory-promoting reflex increased following acute cocaine. / The data suggest that while acute cocaine acts as ventilatory stimulant triggering behavioral polypnea, it depresses ventilation in chronically treated rats.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.59407 |
| Date | January 1989 |
| Creators | Kelly, Gisèle |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001068580, proquestno: AAIMM63579, Theses scanned by UMI/ProQuest. |
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