Oxytocin is a precursor of potent behaviourally active neuropeptides.
An oxytocin fragment which accumulated during the incubation of oxytocin with brain synaptic membranes was chemically characterized as the hexapeptide pGlu-Asn-Cys(Cys)-Pro-Leu-Gly-NH2 [( pGlu4, Cyt6]OXT-(4-9]. This peptide was approximately a hundred times more potent than oxytocin in attenuating memory consolidation as tested in a passive avoidance test situation; the dose-response relationship was bell-shaped. The des-glycinamide derivative [pGlu4, Cyt6]OXT-(4-8) was nearly as active, but showed a linear dose-response relationship. The data indicate that oxytoxin can act as precursor for potent behaviourally active neuropeptides.
D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology*; D005260:Female; D066298:In Vitro Techniques; D007276:Injections, Intraventricular; D008297:Male; D008566:Membranes / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000502:physiology*; D010121:Oxytocin / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism; D051381:Rats; D014590:Uterine Contraction / Q000187:drug effects
D009419:Nerve Tissue Proteins; D011498:Protein Precursors; D010121:Oxytocin