Related Experiment Video
Updated: Aug 21, 2025

In Vivo SiRNA Transfection and Gene Knockdown in Spinal Cord via Rapid Noninvasive Lumbar Intrathecal Injections in Mice
Published on: March 22, 2014
Discovery of κ Opioid Receptor (KOR)-Selective d-Tetrapeptides with Improved In Vivo Antinociceptive Effect after
Azzurra Stefanucci1, Alice Della Valle1, Giuseppe Scioli1
1Dipartimento di Farmacia, Università di Chieti-Pescara "G. d'Annunzio", Via dei Vestini 31, 66100 Chieti, Italy.
Abstract:
Peripherally active tetrapeptides as selective κ opioid receptor (KOR) agonists have been prepared in good overall yields and high purity following solid-phase peptide synthesis via Fmoc protection strategy. Structural modifications at the first and second position of the lead compound FF(d-Nle)R-NH2 (FE200041) were contemplated with aromatic side chains containing d-amino acids, such as (d)-pF-Phe, (d)-mF-Phe, (d)-oF-Phe, which led to highly selective and efficacious KOR agonists endowed with strong antinociceptive activity in vivo following intravenous (i.v.) and subcutaneous (s.c.) administration in the tail flick and formalin tests. These results suggest potential clinical applications in the treatment of neuropathic and inflammatory pain.
More Related Videos
Related Concept Videos
Analgesia and Pain Management
Opioid Receptors: Overview
Opioid Analgesics: Synthetic and Semisynthetic Opioids
Nociception
Opioid Analgesics: Morphine and Other Natural Cogeners
Chemotherapy-Induced Nausea and Vomiting: Neurokinin-1 Receptor Antagonists

