Electrophysiological evidence for kappa-agonist activity of dynorphin in rat brain.
Dynorphin (1-13) and the mu-agonist, FK 33,824, have been applied microiontophoretically to single neurones in the hippocampus of the rat. Whereas FK 33,824 predominantly caused an increase in neuronal firing rates, dynorphin (1-13) decreased activity. Both effects were blocked by the opiate antagonist naloxone, whereas the effects induced by GABA and glutamate were not. This action of dynorphin (1-13) is comparable to that of other kappa-agonists in this brain region and suggests that dynorphin (1-13) may be a ligand for the kappa opiate receptor.
D000818:Animals; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin / Q000494:pharmacology; D004399:Dynorphins; D004723:Endorphins / Q000494:pharmacology*; D006624:Hippocampus / Q000502:physiology; D007478:Iontophoresis; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects*; D017473:Receptors, Opioid, kappa
D004723:Endorphins; D010446:Peptide Fragments; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; D009270:Naloxone; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin; C026843:dynorphin (1-13); D004399:Dynorphins