Release of immunoreactive met-enkephalin by intraventricular beta-endorphin in anesthetized rats.
The release of immunoreactive met-enkephalin and leu-enkephalin from the spinal cord by intraventricular injection of different doses of beta-endorphin was studied using the intrathecal perfusion technique. The intraventricular beta-endorphin elicited the release of immunoreactive met-enkephalin from the spinal cord in a dose dependent manner. Immunoreactive leu-enkephalin in the spinal perfusate was not increased after intraventricular beta-endorphin injection. Both immunoreactive met-enkephalin and leu-enkephalin in the spinal cord were not changed by low doses (2-6 micrograms) of beta-endorphin but were increased markedly by 60-70% after high doses of beta-endorphin (32-64 micrograms). It is likely that the biosynthesis of enkephalins was also increased after intraventricular beta-endorphin injection. Intraventricular naloxone, 30 micrograms did not induce any release of immunoreactive met-enkephalin from the spinal cord and did not block the release of immunoreactive met-enkephalin induced by intraventricular beta-endorphin, 15 micrograms.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D001933:Brain Stem / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004723:Endorphins / Q000008:administration & dosage / Q000494:pharmacology*; D004743:Enkephalin, Leucine / Q000378:metabolism; D004744:Enkephalin, Methionine / Q000378:metabolism*; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D010477:Perfusion; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D014018:Tissue Distribution; D001615:beta-Endorphin
D004723:Endorphins; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; D001615:beta-Endorphin