Stimulation by nerve growth factor of neuropeptide synthesis in the adult rat in vivo: bilateral response to unilateral intraplantar injections.
Unilateral intraplantar injections (1/day for 3 days) of 4 mu g nerve growth factor (NGF) into the rat hindpaw increased the expression of prepro-tachykinin (PPT)- and prepro-calcitonin gene-related peptide (ppCGRP)-mRNA in bilateral L5 dorsal root ganglia (DRGs). This was accompanied by an increase of CGRP-like immunoreactivity in the ipsi- and contralateral sciatic nerve but by no detectable change of CGRP-IR in other afferents. NGF injections into the skin of one ear or into the plantar side of one forepaw increased CGRP-IR in the respective afferents (trigeminal ganglion, or nerves arising from the brachial plexus, respectively), but had no effect on sciatic CGRP-IR. This suggests that the NGF-induced symmetrical increase of CGRP synthesis in L5 DRGs was not caused by systemic action of NGF, which, therefore, may be a useful tool to further investigate mechanisms which are responsible for contralateral effects of unilateral inflammation.
Amann
R
R
Department of Experimental and Clinical Pharmacology, Graz University, Austria.amann@kfunigraz.ac.at
Sirinathsinghji
D J
DJ
Donnerer
J
J
Liebmann
I
I
Schuligoi
R
R
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005727:Ganglia, Spinal / Q000378:metabolism*; D017403:In Situ Hybridization; D008297:Male; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009479:Neuropeptides / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000378:metabolism; D015320:Tachykinins / Q000378:metabolism
D009414:Nerve Growth Factors; D009479:Neuropeptides; D012333:RNA, Messenger; D015320:Tachykinins