Effects of morphine on oedema and tissue concentration of nerve growth factor in experimental inflammation of the rat paw.
Injection of carrageenan (1 mg) into the rat hind paw caused a time-dependent increase in paw volume that was maximal 3 h after injection. At this time, the concentration of nerve growth factor (NGF) in the skin of the inflamed paw was more than twofold higher than in the contralateral, non-inflamed paw. Treatment of rats with indomethacin reduced inflammatory oedema by 57%, morphine treatment attenuated oedema by 62%. While indomethacin had no statistically significant effect on the concentration of NGF in the skin of inflamed paws, morphine attenuated the NGF response by 24.2% in a naloxone reversible manner. These data suggest that drug-induced inhibition of inflammatory oedema is not predictive of its effect on an inflammation-induced rise in tissue NGF. Furthermore, our results confirm and extend previous observations suggesting an anti-inflammatory activity of morphine.
Amann
Rainer
R
Institute for Experimental and Clinical Pharmacology, University of Graz, Austria. rainer.amaann@kfunigraz.ac.at
Lanz
Ilse
I
Schuligoi
Rufina
R
D000818:Animals; D004487:Edema / Q000188:drug therapy* / Q000378:metabolism; D006614:Hindlimb / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D007249:Inflammation / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D009020:Morphine / Q000494:pharmacology / Q000627:therapeutic use*; D020932:Nerve Growth Factor / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D009020:Morphine; D020932:Nerve Growth Factor