Left vagal stimulation induces dynorphin release and suppresses substance P release from the rat thoracic spinal cord during cardiac ischemia

Electrostimulatory forms of therapy can reduce angina that arises from activation of cardiac nociceptive afferent fibers during transient ischemia. This study sought to determine the effects of electrical stimulation of left thoracic vagal afferents (C8-T1 level) on the release of putative nocicepti...

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Bibliographic Details
Published inAmerican journal of physiology. Regulatory, integrative and comparative physiology Vol. 56; no. 6; pp. R1468 - R1477
Main Authors FANG HUA, ARDELL, Jeffrey L, WILLIAMS, Carole A
Format Journal Article
LanguageEnglish
Published Bethesda, MD American Physiological Society 01.12.2004
Subjects
Analgesics
Biological and medical sciences
Cardiology
Coronary vessels
Fundamental and applied biological sciences. Psychology
Heart attacks
Hormones and neuropeptides. Regulation
Hypothalamus. Hypophysis. Epiphysis. Urophysis
Medical sciences
Neurons
Neuropharmacology
Peptides
Pharmacology. Drug treatments
Spinal cord
Vertebrates: endocrinology
Therapy
Spinal cord
Left
Rat
angina
Central nervous system
Cardiovascular disease
Stimulation
analgesic peptides
Activation
Posterior spinal horn
Neuropeptide
Opioid peptide
Ischemia
antibody-coated microprobes
Release
cardiac nervous system
Substance P
Electrical stimulus
Rodentia
nociceptive peptides
Vertebrata
Mammalia
Analgesic
Dynorphin
Tachykinin
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Summary:Electrostimulatory forms of therapy can reduce angina that arises from activation of cardiac nociceptive afferent fibers during transient ischemia. This study sought to determine the effects of electrical stimulation of left thoracic vagal afferents (C8-T1 level) on the release of putative nociceptive [substance P (SP)] and analgesic [dynorphin (Dyn)] peptides in the dorsal horn at the T4 spinal level during coronary artery occlusion in urethane-anesthetized Sprague-Dawley rats. Release of Dyn and SP was measured by using antibody-coated microprobes. While Dyn and SP had a basal release, occlusion of the left anterior descending coronary artery only affected SP release, causing an increase from lamina I-VII. Left vagal stimulation increased Dyn release, inhibited basal SP release, and blunted the coronary artery occlusion-induced release of SP. Dyn release reflected activation of descending pathways in the thoracic spinal cord, because vagal afferent stimulation still increased the release of Dyn after bilateral dorsal rhizotomy of T2-T5. These results indicate that electrostimulatory therapy, using vagal afferent excitation, may induce analgesia, in part, via inhibition of the release of SP in the spinal cord, possibly through a Dyn-mediated neuronal interaction. [PUBLICATION ABSTRACT]
ISSN:0363-6119
1522-1490