Involvement of interleukin-1 beta, nerve growth factor, and prostaglandin-E2 in the hyperalgesia induced by intraplantar injections of low doses of thymulin.

Abstract

The effect of various doses of intraplantar thymulin injection, on nociceptive thresholds, in the hind paw of rats was assessed using different pain tests. As little as 0.5 ng thymulin resulted in localized mechanical hyperalgesia as assessed by the paw pressure test and thermal hyperalgesia as assessed by the paw immersion, hot plate, and tail flick tests. The highest dose of thymulin (10 ng) reduced both paw pressure and paw immersion latencies in the noninjected paw also. Thymulin (5 ng) also resulted in significant elevation in the levels of interleukin-1 beta (IL-1 beta) and nerve growth factor (NGF) levels in the injected paw. Both dexamethasone and indomethacin reversed thymulin-induced hyperalgesia. Also interleukin-1 receptor antagonist (IL-1ra) and a polyclonal anti-NGF antiserum significantly reduced thymulin-induced hyperalgesia. On the other hand, the tripeptide lys-D-pro-val (known to antagonize IL-1 beta and PGE2 induced hyperalgesia) reversed the hyperalgesia due to thymulin. In conclusion, thymulin induces localized hyperalgesia which is mediated by PGE2-dependent mechanisms and this pathway could be either partially dependent on or totally independent of IL-1 beta mechanisms.

• Authors: B Safieh-Garabedian, S A Kanaan, R H Jalakhian, S J Jabbur, N E Saadé
• Journal: Brain, behavior, and immunity (Brain Behav Immun) Vol. 11 Issue 3 Pg. 185-200 (Sep 1997) ISSN: 0889-1591 [Print] Netherlands
• PMID: 9417804 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Inflammatory Agents
• Anti-Inflammatory Agents, Non-Steroidal
• Interleukin-1
• Nerve Growth Factors
• Prostaglandin Antagonists
• Dexamethasone
• Thymic Factor, Circulating
• Dinoprostone
• Indomethacin

Topics

• Animals
• Anti-Inflammatory Agents (therapeutic use)
• Anti-Inflammatory Agents, Non-Steroidal (therapeutic use)
• Behavior, Animal (drug effects)
• Dexamethasone (therapeutic use)
• Dinoprostone (metabolism, physiology)
• Hyperalgesia (chemically induced, metabolism, physiopathology)
• Indomethacin (therapeutic use)
• Interleukin-1 (antagonists & inhibitors, metabolism, physiology)
• Male
• Nerve Growth Factors (antagonists & inhibitors, metabolism, physiology)
• Pain Measurement (drug effects)
• Prostaglandin Antagonists (pharmacology)
• Rats
• Rats, Sprague-Dawley
• Thymic Factor, Circulating (administration & dosage)