To determine the origin of non-vagal afferent fibers innervating the heart of guinea pigs, capsaicin was injected into the ventricular myocardium to induce depletion of substance P (SP). The lower cervical, upper thoracic and lumbar spinal ganglia, as well as the left atrium and base of ventricles, were assayed for SP depletion by using the enzyme-linked immunosorbent assay (ELISA) and immunohistochemical procedures. Capsaicin affected spinal ganglia from the 3 regions differently. The substance P level in lumbar spinal ganglia remained fairly constant, while the level of SP from cervical and thoracic regions declined significantly. At the maximal depletion dosage (173 μg of capsaicin/kg), SP concentration decreased 72.3% in cervical spinal ganglia, 45.5% in thoracic ganglia and 56.1% in the atrium. The lack of SP depletion in lumbar ganglia indicates that capsaicin acted locally on cardiac afferents rather than systemically. Data from this study suggest that capsaicin-sensitive neurons of the heart have cell bodies in the lower cervical spinal ganglia as well as in the upper thoracic spinal ganglia.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-14056 |
| Date | 01 January 1986 |
| Creators | Hougland, Margaret W., Durkee, Kristine H., Hougland, Arthur E. |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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