Background & Aims

In HIV neuropathy, chronic pain is one of the most prevalent neurological complications of HIV infection even in the era of combination antiretroviral therapy. Repeated use of opioid pain medications can increase neuropathic pain in people living with HIV. The exact mechanisms of the persistent and complexed HIV chronic pain state remain elusive. There is currently a lack of effective therapy for HIV pain. Recent studies have indicated that cannabinoid receptor type 1/2 (CB1/2R) agonists reduce nerve injury-related pain. In the present study, we investigated the effects of CB1/2R agonists in HIV-related neuropathic pain model in rats and mice.

Methods

In rats model, male and female SD rats received intrathecal recombinant gp120MN ((an X4- and R5 dual-tropic gp120) followed by morphine for 5 days (gp120/M). Mechanical threshold was measured using von Frey filament and was determined using the up-and-down methods. Thermal latency was tested using hot plate test. In mice model, mice received intrathecal gp120 with morphine once a day for 3 days. Paw withdrawal frequency in response to mechanical stimuli were measured with two calibrated von Frey filaments (0.07 and 0.4 g). Either CB1 receptor agonist ACEA or CB2 receptor agonist LY2828360 was injected intrathecally.

Results

Application of gp120/M induced mechanical allodynia and thermal hyperalgesia in rats and mice. Single injection of either ACEA or LY2828360 suppressed mechanical allodynia and thermal hyperalgesia in rats and mice. Repeated injection of ACEA for 7 days induced antinociceptive tolerance, however, CB2 receptor agonist LY2828360 did not show the antinociceptive tolerance response in HIV pain model.

Conclusions

Current preliminary data suggest that both CB1/2 agonists produced analgesia, but chronic ACEA for induced antinociceptive tolerance in HIV-related neuropathic pain model. We will continue to study the molecular mechanisms of HIV-related pain.

No Conflict(s) of Interest in the research.
The work is partially supported by R01DA047157 and VA 1I01BX005114.

References

N/A

Presenting Author

Shuanglin Hao

Poster Authors

Shuanglin Hao

PhD

University of Miami, and Miami VA Healthcare System, FL

Lead Author

Kentaro Hayashi

University of Miami

Lead Author

Xun Zhu

University of Miami

Lead Author

Jun Gu

University of Miami

Lead Author

Hyun Yi

University of Miami

Lead Author

Shue Liu

University of Miami

Lead Author

Roy C. Levitt

University of Miami

Lead Author

Topics

  • Specific Pain Conditions/Pain in Specific Populations: Neuropathic Pain - Central