Dynorphin A(1-13), a version of dynorphin A containing only the first 13 amino acids of the peptide, in the rat spinal cord has additive effects. When dynorphin A1-13 was injected into the intracerebroventriulcar (ICV) region of the brain, it has an antagonist effect on morphine-induced analgesia.https://www.creative-peptides.com/product/dynorphin-a-item-10-101-12-42.html
