Mechanisms regulating spinal sympathetic output to the heart and vessels have been examined using the technique of intrathecal administration of neuroactive agents at T2 and/or T9 in the rat. Antagonists and/or agonists of glycine, GABA$ sb{ rm A},$ GABA$ sb{ rm B}$ and excitatory amino acid receptors have been studied to determine how the respective amino acids mechanisms function at the spinal level to regulate sympathetic output. The results indicated that glycine, GABA$ sb{ rm A},$ GABA$ sb{ rm B},$ novel GABA, D-baclofen-sensitive, NMDA and non-NMDA receptors are involved in regulation of sympathetic output at the spinal level. Glycine, GABA$ sb{ rm A},$ GABA$ sb{ rm B},$ NMDA and non-NMDA receptors also participate in regulation of arterial pressure and heart rate under basal conditions. As D-baclofen increases only arterial pressure, it is proposed that there is a differential distribution of some receptors on the sympathetic neurons innervating different end organs. In addition, as the antagonists strychnine and APV alter either heart rate or arterial pressure, it is proposed that different receptors differ in their degree of tonic activation.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.70201 |
| Date | January 1990 |
| Creators | Hong, Yanguo |
| 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: 001242567, proquestno: AAINN72029, Theses scanned by UMI/ProQuest. |
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