Related Experiment Video
Updated: Aug 11, 2026

In Vivo SiRNA Transfection and Gene Knockdown in Spinal Cord via Rapid Noninvasive Lumbar Intrathecal Injections in Mice
Published on: March 22, 2014
Endomorphin-1 induces antinociception without immunomodulatory effects in the rat
K A Carrigan1, C J Nelson, D T Lysle
1Department of Psychology, University of North Carolina at Chapel Hill, 27599-3270, USA. kelly@isis.unc.edu
Endomorphin-1 effectively reduces pain in rats, but does not impact immune responses. This suggests potential for developing pain-relieving drugs that avoid immune system effects.
Area of Science:
- Neuroscience
- Immunology
- Pharmacology
Background:
- Central opioid receptors play a role in immunomodulation.
- Endomorphin-1 is an endogenous agonist with high affinity for mu opioid receptors.
Purpose of the Study:
- To assess the immunomodulatory effects of endomorphin-1 in rats.
- To further evaluate the antinociceptive effects of endomorphin-1.
Main Methods:
- Rats received intracerebroventricular (ICV) injections of endomorphin-1.
- Antinociception was measured using warm water tail withdrawal and hotplate assays.
- Immune status was assessed by measuring natural killer cell activity, interferon-gamma production, and lymphocyte proliferation.
Main Results:
- Endomorphin-1 produced significant, naltrexone-reversible antinociception.
- No immunomodulatory effects were observed up to 120 minutes post-administration.
Conclusions:
- Endomorphin-1 induces antinociception but not immunomodulation in rats.
- Therapeutic strategies may separate mu opioid receptor-mediated antinociception from immunomodulatory properties.
More Related Videos
07:23Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
Published on: July 29, 2014
08:16Partial Sciatic Nerve Ligation: A Mouse Model of Chronic Neuropathic Pain to Study the Antinociceptive Effect of Novel Therapies
Published on: October 6, 2022
Related Concept Videos
Nociception
Analgesia and Pain Management