Neuropeptide FF reverses the effect of mu-opioid on Ca2+ channels in rat spinal ganglion neurones.
Single neurones isolated from spinal ganglia of young rats were loaded with Fluo3, a fluorescent indicator of intracellular Ca2+ concentration. In 27 of 47 neurones the depolarization-evoked rise in fluorescence was reduced by 47.8 +/- 3.3% by prior perfusion with DAGO (1 microM, 30 s) a mu-opioid agonist. In 12 neurones an analogue of neuropeptide FF ((1DMe)Y8Fa, 10 nM, 30 min) did not affect the Ca2+ response to depolarization. (1DMe)Y8Fa reversed the effect of DAGO by 63 +/- 8% in seven of these 12 neurones. We conclude that stimulation of neuropeptide FF receptors antagonizes mu-opioid modulation of Ca2+ channels at the cellular level.
Rebeyrolles
S
S
Institut de Pharmacologie et de Biologie Structurale, Toulouse, France.
Zajac
J M
JM
Roumy
M
M
D000700:Analgesics; D000814:Aniline Compounds; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism*; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004745:Enkephalins / Q000037:antagonists & inhibitors / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017450:Receptors, Opioid, mu / Q000819:agonists*; D014966:Xanthenes
D000700:Analgesics; D000814:Aniline Compounds; D015220:Calcium Channels; D004745:Enkephalins; D009292:Narcotic Antagonists; D009294:Narcotics; D009842:Oligopeptides; D017450:Receptors, Opioid, mu; D014966:Xanthenes; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; C059715:Fluo-3; D011189:Potassium Chloride; C053651:phenylalanyl-leucyl-phenylalanyl-glutaminyl-prolyl-glutaminyl-arginyl-phenylalaninamide