TY - JOUR
T1 - Influence of morphine on the activity of low-threshold visceral mechanoreceptors in cats with acute pericarditis
AU - Bałkowiec, Agnieszka
AU - Kukuła, Krzysztof
AU - Szulczyk, Paweł
N1 - Funding Information:
We would like to expresso ur gratitudet o Prof. K. Wjodarski and Dr. B. Gornicka for invaluableh elp in the histological evaluationo f heart tissues.W e also thank G. Malczyk and J. Kaczmarczykf or technical assistanceT. he work was supported by KBN Grant 0655P2-92-02.
PY - 1994/11
Y1 - 1994/11
N2 - The purpose of this investigation was to test whether morphine (morphinum hydrochloricum) applied to the receptive field of the thoracic visceral afferent fibres modifies their activity. Experiments were performed on chloralose-anaesthetised cats, paralysed and artificially ventilated, in a state of pericarditis that was induced by intrapericardial injection of λ-carrageenan and kaolin. Resulting acute inflammation was proven histopathologically and documented electrocardiographically. Single afferent fibres with receptive fields in thoracic viscera were dissected from thoracic sympathetic chain (19 fibres), as well as the vagus nerve (9 fibres). All tested fibres transmitted sensory information from the low-threshold mechanoreceptors. As a final result, it was found that morphine (0.001-1.0 mg/ml) when applied locally activates, depending on the dose, afferent fibres as follows: 12 sympathetic afferents (out of 12 tested), and 7 vagal afferents (out of 9 tested). In examining the specificity of morphine action, the preliminary local application of naloxone (1.0 mg/ml) just before morphine, blocked all excitatory responses. The excitatory response was present whether the receptive field was located in the inflammatory area, or outside it, in group III or IV fibres.
AB - The purpose of this investigation was to test whether morphine (morphinum hydrochloricum) applied to the receptive field of the thoracic visceral afferent fibres modifies their activity. Experiments were performed on chloralose-anaesthetised cats, paralysed and artificially ventilated, in a state of pericarditis that was induced by intrapericardial injection of λ-carrageenan and kaolin. Resulting acute inflammation was proven histopathologically and documented electrocardiographically. Single afferent fibres with receptive fields in thoracic viscera were dissected from thoracic sympathetic chain (19 fibres), as well as the vagus nerve (9 fibres). All tested fibres transmitted sensory information from the low-threshold mechanoreceptors. As a final result, it was found that morphine (0.001-1.0 mg/ml) when applied locally activates, depending on the dose, afferent fibres as follows: 12 sympathetic afferents (out of 12 tested), and 7 vagal afferents (out of 9 tested). In examining the specificity of morphine action, the preliminary local application of naloxone (1.0 mg/ml) just before morphine, blocked all excitatory responses. The excitatory response was present whether the receptive field was located in the inflammatory area, or outside it, in group III or IV fibres.
KW - Mechanoreceptor
KW - Morphine
KW - Naloxone
KW - Pericarditis
KW - Sympathetic afferent
KW - Vagal afferent
UR - http://www.scopus.com/inward/record.url?scp=0027987377&partnerID=8YFLogxK
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U2 - 10.1016/0304-3959(94)90078-7
DO - 10.1016/0304-3959(94)90078-7
M3 - Article
C2 - 7892023
AN - SCOPUS:0027987377
SN - 0304-3959
VL - 59
SP - 251
EP - 259
JO - Pain
JF - Pain
IS - 2
ER -