This thesis investigates the effects of substance P on a spinal nociceptive reflex in the rat. Intrathecal administration of substance P and other analogous peptides to the L5 vertebral level produced a dose-dependent decrease in reaction time to tail withdrawal from a noxious radiant heat source. Similar administration of VIP, galanin, CGRP, angiotensin II, somatostatin and TRH failed to mimic these effects of substance P. As substance P was found to equally decrease the reaction time in spinal transected rats, it is concluded that this facilitation occurs via a spinal mechanism alone. / Administration of substance P at the lower thoracic level increased reaction time. Evidence is provided to suggest that this increase in reaction time may involve the release of an opioid peptide into the circulation from the adrenal medullae. / Noxious cutaneous stimulation to the tail of anaesthetized rat produced a facilitation of the tail flick reflex which was similar to that induced by exogenous administration of substance P. This decrease in reaction time was attenuated by intrathecal administration of a substance P antagonist. / These results support an earlier hypothesis made by others that substance P may be involved in the transmission of nociceptive information in the spinal cord.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.75692 |
| Date | January 1987 |
| Creators | Cridland, Ruth Anne |
| 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 | Doctor of Philosophy (Department of Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000570454, proquestno: AAINL46043, Theses scanned by UMI/ProQuest. |
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