Co-application of lidocaine and QX-572 induces divergent pain behaviours in mice.

Abstract

OBJECTIVES:

We investigated the analgesic effects of lidocaine (LDC) and lidocane derivative, QX-572, co-application on the evoked pain behaviour (complete Freund's Adjuvant (CFA)-induced) and spontaneous pain behaviour (formalin-induced) in mice.

METHODS:

The experiments were performed using adult male Kunming mice. Formalin-induced acute pain model and CFA-induced chronic pain model was established by injecting formalin and CFA, respectively. Separate injections of LDC and QX-572, or co-injection of LDC and QX-572, were performed to observe the differences in neurobehavioural responses, paw withdrawal latency (PWL) and mechanical withdrawal threshold (MWT).

KEY FINDINGS:

QX-572 injection alone did not influence PWL and MWT, but injection of LDC alone led to a substantial, but short-lived, elevation in PWL and MWT (45 min). Co-injection of LDC and QX-572, however, resulted in a significant increase in PWL and MWT (120 min) compared with the LDC group. Injection of LDC and QX-572 combination in the adjacent sciatic nerve also produced a long-lasting sensory-specific nerve block. Additionally, intraplantar co-injection of LDC and QX-572 combination inhibited spontaneous pain in formalin-treated mice, but did not detectably attenuated hyperalgesia and allodynia in CFA-treated mice.

CONCLUSIONS:

Our results provide evidence that QX-572 induced sensory-selective blockade and co-injection of QX-572 and LDC enhance pain blockade, as evident from formalin-treated mice.

• Authors: Cui-Jie Shao, Yong Gao, Li Zhao, Dan Jin, Dan Wang, De-Qiang Wang
• Journal: The Journal of pharmacy and pharmacology (J Pharm Pharmacol) Vol. 67 Issue 9 Pg. 1272-8 (Sep 2015) ISSN: 2042-7158 [Electronic] England
• PMID: 25904024 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 Royal Pharmaceutical Society.

Chemical References

• Anesthetics, Local
• Freund's Adjuvant
• Lidocaine
• carcainium chloride

Topics

• Anesthetics, Local (pharmacology)
• Animals
• Freund's Adjuvant (pharmacology)
• Injections (methods)
• Lidocaine (administration & dosage, analogs & derivatives)
• Male
• Mice
• Nerve Block (methods)
• Pain (drug therapy)
• Pain Measurement (drug effects)
• Sciatic Nerve (drug effects)