Ruthenium red selectively inhibits capsaicin-induced release of calcitonin gene-related peptide from the isolated perfused guinea pig lung.
In the present study the influence of Ruthenium red on capsaicin- and bradykinin-evoked neuropeptide release from primary afferent neurons was investigated in the guinea pig. Perfusion of the isolated guinea pig lung in vitro with a capsaicin (1 microM)-containing physiological salt solution increased the amount of calcitonin gene-related peptide-like immunoreactivity (CGRP-IR) in the outflow more than 20-fold. Ruthenium red (RR: 1 microM, 10 microM) dose-dependently reduced capsaicin-induced release of CGRP-IR. Addition of bradykinin (1 microM) to the perfusate induced a 3-fold increase of CGRP-IR in the outflow, which was not significantly reduced by 10 microM RR. These results suggest that RR represents a rather specific antagonist of capsaicin's action on sensory neurons.
Amann
R
R
Department of Experimental and Clinical Pharmacology, University of Graz, Austria.
Donnerer
J
J
Lembeck
F
F
D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin / Q000494:pharmacology*; D004347:Drug Interactions; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008168:Lung / Q000294:innervation*; D009475:Neurons, Afferent / Q000187:drug effects / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D012428:Ruthenium / Q000494:pharmacology*; D012430:Ruthenium Red / Q000494:pharmacology*
D009479:Neuropeptides; D012430:Ruthenium Red; D012428:Ruthenium; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin; D001920:Bradykinin