Dermorphin inhibits spinal nociceptive flexion reflex in humans.
Dermorphin (D) is a potent opiate-like peptide isolated from the skin of some species of frogs. Experimental studies in animals indicate that D has a potent antinociceptive effect, while no investigation exists about its analgesic properties in humans. Our study shows that i.v. infusion of 0.16 mg/kg D induces a marked and long-lasting increase in the threshold of nociceptive flexion reflex in healthy volunteers. This effect is also evident in a complete chronic spinal subject, showing that D depresses the nociceptive transmission mainly acting at spinal level. Naloxone, while fully antagonizing the effects of morphine and enkephalin analogue, is able to reverse only partly (ca. 50%) the depressive effect of D on nociceptive spinal reflex. This fact may suggest that D interacts with different spinal opiate receptor populations in inducing analgesia.
G
G
Sandrini
E C
EC
Degli Uberti
S
S
Salvadori
A
A
Margutti
G
G
Trasforini
R
R
Tomatis
G
G
Nappi
R
R
Pansini
D000328:Adult; D006801:Humans; D007263:Infusions, Parenteral; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects; D009619:Nociceptors / Q000187:drug effects*; D009842:Oligopeptides / Q000008:administration & dosage / Q000494:pharmacology*; D018847:Opioid Peptides; D010264:Paraplegia / Q000503:physiopathology; D012018:Reflex / Q000187:drug effects*; D013116:Spinal Cord / Q000187:drug effects*; D013997:Time Factors
D009842:Oligopeptides; D018847:Opioid Peptides; C030058:dermorphin